第一节 自然科学类--必备知识
Unit 11 Natural Science--Prerequisites
本节主要目标 Lesson Aim
了解如何快速阅读 ACT 阅读的自然科学类篇章，并抓住重点；
讲解自然科学篇章的常考知识点；
学会预测考点。
Pre-learning Vocabulary
Word
Part of
Phrase
Meaning
Word
Part of
speech
Phrase
speech
uncannily
adv
dowry
adj
speculate
v
scenario
n
whittle away
v phr
hypothesize
v
succession
n
asteroid
n
comet
n
crater
n
velocity
n
projectile
adj
vaporize
v
shove
v
wispy
adj
bounce off
v phr
thaw out
v phr
terrestrial
adj
* 单词的顺序按在 passage 里面出现的顺序。
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Meaning
11.1 自然科学篇章简介
永远是最后一篇文章。
一般难度与社科类文章持平，低于文学类和人文科学类。
整体阅读顺序安排：
（常规）__________________________
（科学类较强）__________________________
或 __________________________
11.2 自然科学篇章必备知识
自然科学篇章大多有__________________________ 和__________________________ 。
做题顺序：（平均每篇做题 8.5 分钟，包括阅读+做题）
快速阅读一遍文章（3.5 分钟）；
做题（5 分钟），平均每题 30 秒。
变通方法：3.5 分钟快速阅读，读到哪里算哪里。
快速阅读时，须迅速整理出__________________________。
好处：
1. 放弃细节抓主干，更高效记住信息。
2. 减少阅读时间，加强对文章理解。
3. 预判考点。
常见文章结构和构成成分：
1. 实验发现类
类似____________________________________________________的文章。
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hook /
background
information
scientific phenomenon, unsolved p__________, old
f__________, current situation
research p____________________
h____________________
Main body:
Research focus
s_____________
research steps
m_____________
findings
+
a____________________ (reasons)
e_____________ /a_____________ / l_____________ / i_____________
2. 科学现象
类似____________________________
说明事物的概念、结构、形态、性质、功用、方法、发展变化等等
例如：水的循环
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Exercise：Read the following passage, and fill in its mindmap.
NATURAL SCIENCE: This passage is adapted from the article "The Mars Model" by Bridget Mintz
Testa, which appears in Discover Magazine (©1995 by The Walt Disney Company).
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Passage IV
NATURAL SCIENCE: This passage is adapted from the
article "The Mars Model" by Bridget Mintz Testa,
which appears in Discover Magazine (©1995 by The
Walt Disney Company).
5
10
15
20
25
30
35
40
45
94
The first close-up images of Mars, captured in 1972
by the probe Mariner 9, were a planetary scientist's
dream: they revealed networks of valleys that looked
uncannily like drainage basins and streambeds back
here on Earth and thus implied that there had once
been water freely flowing over the surface of Mars.
The images also implied that Mars had once had a
thick atmosphere. Our planet is blessed with liquid
water on its surface only because it has a thick
atmosphere to maintain a high pressure and trap the
sun's heat. So planetary scientists proposed that
when Mars formed 4.6 billion years ago, it too had a
dowry of a heat-trapping atmosphere, composed of
carbon dioxide and water vapor. With warmth, water,
and air, they speculated, Mars might once have been
a garden world, a paradise among planets.
Paragraph 1 and 2
What is the main idea of the two paragraphs?
__________________________________________________________
________________________________________________________
Based on this passage, what is the function of the
paragraphs?
__________________________________________________________
________________________________________________________
What is their relationship with other paragraphs?
__________________________________________________________
________________________________________________________
But, as they also discovered, the garden didn't last
long. None of the streambeds were younger than 3.7
billion years. Something happened to Mars,
something that stripped nearly all of its atmosphere,
killed its streams, and froze the garden forever.
Researchers have suggested many scenarios for
the Martian apocalypse. Some have proposed that
the sun gradually whittled away Mars' atmosphere
with its wind of charged particles. Others have
hypothesized that the planet itself absorbed most of
its atmosphere, turning carbon dioxide into
carbonate rocks. For the past seven years, however,
Ann Vickery and Jay Melosh, two planetary scientists
from the University of Arizona, have been exploring a
far more spectacular ending: most of Mars'
atmosphere, they suggest, was blasted away by a
succession of asteroids and comets.
Paragraph 3 and 4
What is the main idea of the two paragraphs?
__________________________________________________________
________________________________________________________
Based on this passage, what is the function of the
paragraphs?
__________________________________________________________
________________________________________________________
What is their relationship with other paragraphs?
__________________________________________________________
________________________________________________________
"The basic idea," Melosh says, "is that an impact
doesn't just open a crater. With high velocities, the
projectile vaporizes and expands into the
atmosphere." This superheated expanding plume
shoves the atmosphere above it like a snowplow
pushing snow to the heavens. How high a vapor
plume goes depends on the mass and velocity of the
object that crashed into the planet. If it is big enough
and fast enough, it can drive its plume straight back
up into space. The portion of the atmosphere it
plows away is then stripped from the planet forever.
To see if this process could account for Mars'
missing atmosphere, Vickery and Melosh essentially
Paragraph 5
What is the main idea of this paragraph?
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75
80
85
90
ran a film of the Red Planet in reverse, starting with
today's wispy atmosphere and adding back the air
that might have been removed by impacts over the
eons. First they derived a mathematical expression
relating time to the rates of both impacts and
atmosphere loss. Using this expression, they then ran
the clock backward to find out how long it would
take to "grow" an ancient, Earth-like atmosphere
from Mars' current tiny one. If their model was right,
it would produce the original, early Mars. And the
time it took to "grow" a thick atmosphere by going
backward would be the same as the time it took to
lose a thick atmosphere, traveling forward. Using an
impact rate that prevailed 3.7 billion years ago—one
impact every 10,000 years—Vickery and Melosh were
able to start with a virtually dead planet and grow a
thick atmosphere in only 600 or 700 million years.
__________________________________________________________
________________________________________________________
However, now that an attractive explanation finally
exists for how the young paradise of Mars was
destroyed, some researchers are questioning
whether that paradise ever existed in the first place.
Studies of other stars suggest that the young sun was
25 to 30 percent dimmer than it is today. Mars, which
is 49 million miles farther from the sun than is Earth,
would have been receiving less than a third of the
sunlight we now enjoy. Some scientists have
calculated that given so little sunlight, Mars'
atmosphere wouldn't be able to trap enough heat to
keep water from freezing and that under such
conditions, carbon dioxide would form frozen clouds.
What little sunlight Mars received would bounce off
the clouds, and the planet would cool even further.
As to how the Martian valleys we see today might
have formed without a warm atmosphere, it is
suggested that the planet might have been covered
by large expanses of ice and that the heat from Mars'
interior could have thawed out hidden channels.
Paragraph 6
What is the main idea of this paragraph?
__________________________________________________________
________________________________________________________
Vickery, however, is sticking by her original
assumptions. "There exist on Mars valley networks
that look like terrestrial river valley networks and
don't look like any other kind of feature found
anywhere else in the solar system," she points out.
"The first, obvious interpretation is that these
networks were formed more or less the same way as
similar terrestrial networks."
Paragraph 7
What is the main idea of this paragraph?
__________________________________________________________
Based on this passage, what is the function of the
paragraph?
__________________________________________________________
What is its relationship with other paragraphs?
__________________________________________________________
Based on this passage, what is the function of the
paragraph?
__________________________________________________________
________________________________________________________
What is its relationship with other paragraphs?
__________________________________________________________
_________________________________________________________
Based on this passage, what is the function of the
paragraph?
__________________________________________________________
________________________________________________________
What is its relationship with other paragraphs?
__________________________________________________________
____________________________________________________
Reading Comprehension
Based on the above analysis, fill in the blanks to finish the mindmap of the passage. The first letter
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of the words, which can be found in the passage, has been given.
Old findings:
Para1-2
1. networks of v___________________
background
2. young s___________________
information
Previous hypotheses:
h___________________ atmosphere, with carbon dioxide and
water vapor; a g___________________ world
Previous hypotheses
Reason 1: the sun’s wind of c______________ p________________
Reason 2: atmosphere a__________________ by Mars itself
Para 3-4
Main body
Research focus:
current hypothesis: atmosphere b______________ away by
a______________ and c______________
explanations from researchers
Research purpose: to testify if this hypothesis could
Para 5
Research steps
a______________ f________ Mars' missing atmosphere
Process: r______________ a film of Mars → d______________ a
mathematical expression → run the clock b______________
→ verify the hypothesis
Refutation: valley networks not f______________ anywhere
else in the solar system
Para 6-7
Evaluation
Doubts: p______________ not existed
Evidence: studies of other s______________
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本节回顾 Lesson Review
1. 自然科学类篇章，类似其他科学类文章，尤其类似社科类的新发现文
章。
2. 速读时注意两点：第一段认真读；下面段落重点看头看尾看中间。
3. 文章写作风格：语言客观直白，专业术语较多，但大多不影响理解。
4. 文章的主题大多是自然科学实验或发现，或自然现象。
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第十二节 自然科学类--篇章精读 1
Unit 12 Natural Science--Intensive Reading 1
本节主要目标 Lesson Aim
通过精讲一篇经典的自然科学类文章，帮助你
1. 运用之前所学的阅读策略、自然科学知识来分析文章和考题；
2. 了解自然科学类文章的一般结构和考点；
3. 掌握长难句和词汇。
Pre-learning Vocabulary
Vocabulary in the passage
98
Word
Part of
Phrase
Meaning
Word
Part of
speech
Phrase
speech
Leviathan
n
treatise
n
sperm whale
n phr
humpback
n
beluga
n
muffled
adj
spermaceti
n
cavity
n
saturated
adj
branch away
v phr
blowhole
n
sac
n
amplify
v
squeaky
adj
imminent
adj
signify
v
clan
n
matrilineal
adj
Meaning
coda
n
variant
adj
celebrated
adj
antagonism
n
Word
Part of
* 单词的顺序按在 passage 里面出现的顺序。
Vocabulary in test questions
Word
Part of
Meaning
Phrase
speech
Phrase
speech
outline
v
anatomy
n
socialization
n
identifier
n
melodic
adj
enigmatic
adj
* 单词的顺序按在 test questions 里面出现的顺序。
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Meaning
Passage IV
NATURAL SCIENCE: This passage is adapted from the
article "Call of the Leviathan" by Eric Wagner(©2011
by Smithsonian Institution).
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20
25
30
35
40
45
10
In 1839, in the first scientific treatise on the sperm
whale, Thomas Beale, a surgeon aboard a whaler,
wrote that it was "one of the most noiseless of
marine animals." While they do not sing elaborate
songs, like humpbacks or belugas, in fact they are not
silent. Whalers in the 1800s spoke of hearing loud
knocking, almost like hammering on a ship's hull,
whenever sperm whales were present. Only in 1957
did two scientists from the Woods Hole Oceanographic
Institution confirm the sailors' observations. Aboard a
research vessel, the Atlantis, they approached five
sperm whales, shut off the ship's motors and listened
with an underwater receiver. At first, they assumed
the "muffled, smashing noise" they heard came from
somewhere on the ship. Then they determined the
sounds were coming from the whales.
1. Why does the author mention humpbacks or
belugas in line 5?
__________________________________________________________
__________________________________________________________
Biologists now believe that the sperm whale's
massive head functions like a powerful telegraph
machine, emitting pulses of sound in distinct
patterns. At the front of the head are the spermaceti
organ, a cavity that contains the bulk of the whale's
spermaceti, and a mass of oil-saturated fatty tissue.
Two long nasal passages branch away from the bony
nares of the skull, twining around the spermaceti
organ and the fatty tissue. The left nasal passage
runs directly to the blowhole at the top of the whale's
head. But the other twists and turns, flattens and
broadens, forming a number of air-filled sacs capable
of reflecting sound. Near the front of the head sit a
pair of clappers called "monkey lips."
3. What is the relationship between this paragraph and
the previous one?
__________________________________________________________
__________________________________________________________
__________________________________________________________
__________________________________________________________
Sound generation is a complex process. To make its
clicking sounds, a whale forces air through the right
nasal passage to the monkey lips, which clap shut.
The resulting click! bounces off one air-filled sac and
travels back through the spermaceti organ to
another sac nestled against the skull. From there, the
click is sent forward, through the fatty tissue, and
amplified out into the watery world. Sperm whales
may be able to manipulate the shape of both the
spermaceti organ and the fatty tissue, possibly
allowing them to aim their clicks.
5. What is the function of this paragraph?
__________________________________________________________
__________________________________________________________
__________________________________________________________
__________________________________________________________
Biologist Dr. Hal Whitehead has identified four
patterns of clicks. The most common clicks are used
for long-range sonar. So-called "creaks" sound like a
squeaky door and are used at close range when prey
capture is imminent. "Slow clicks" are made only by
large males, but no one knows precisely what they
signify. ("Probably something to do with mating,
6. What are the four patterns of clicks?
__________________________________________________________
__________________________________________________________
2. What is the two scientists’ discovery about sperm
whales?
__________________________________________________________
__________________________________________________________
4. Read the paragraph, and finish Exercise 1 in 12.1
Reading Comprehension.
50
'Whitehead guesses.) Finally, "codas" are distinct
patterns of clicks most often heard when whales are
socializing.
Codas are of particular interest. Whitehead has
found that different groups of sperm whales, called
vocal clans, consistently use different sets; the
repertoire of codas the clan uses is its dialect. Vocal
clans can be huge—thousands of individuals spread
out over thousands of miles of ocean. Clan members
are not necessarily related. Rather, many smaller,
durable matrilineal units make up clans, and different
clans have their own specific ways of behaving.
7. Why are scientists have particular interest in codas?
__________________________________________________________
__________________________________________________________
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A recent study in Animal Behaviour took the
specialization of codas a step further. Not only do
clans use different codas, the authors argued, but the
codas differ slightly among individuals. They could
be, in effect, unique identifiers: names.
8. What is the scientific implication of this recent
study?
__________________________________________________________
__________________________________________________________
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Whitehead cautions that a full understanding of
codas is still a long way off. Even so, he believes the
differences represent cultural variants among the
clans. "Think of culture as information that is
transmitted socially between groups," he says. "You
can make predictions about where it will arise: in
complex societies, richly modulated, among
individuals that form self-contained communities."
That sounds to him a lot like sperm whale society.
9. What is the limitation for scientific research on
codas now?
__________________________________________________________
__________________________________________________________
But most of a sperm whale's clicking, if not most of
its life, is devoted to one thing: finding food. And in
the Sea of Cortez, the focus of its attention is
Dosidicus gigas, the jumbo squid.
10. What is the purpose of clicking?
__________________________________________________________
__________________________________________________________
The most celebrated natural antagonism between
sperm whales and squid almost certainly involves the
jumbo squid's larger cousin, the giant squid, a
species that grows to 65 feet long. The relationship
between sperm whales and squid is pretty dramatic.
A single sperm whale can eat more than one ton of
squid per day. They do eat giant squid on occasion,
but most of what whales pursue is relatively small
and over-matched. With their clicks, sperm whales
can detect a squid less than a foot long more than a
mile away, and schools of squid from even farther
away. But the way that sperm whales find squid was
until recently a puzzle.
11. How do sperm whales use their clicks in hunting?
__________________________________________________________
__________________________________________________________
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75
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85
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12.1 Reading Comprehension
1. Based on Paragraph 2 of Passage A, fill in the blanks A, B and C in the following picture of the
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sperm whale’s head.
A:______________________________________
B:______________________________________
C:______________________________________
2. Based on the above analysis, fill in the blanks to finish the mindmap of the passage. The first letter
of the words, which can be found in the passage, has been given.
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Para1
It was misunderstood that sperm whales were s_________,
background
but sailors’ observation and scientific finding
information
confirmed that they could make l_________ k_________.
Sperm whales’ head functions as the sound-making
device, including spermaceti organ, f_________ t______,
the left and right n_________ p_________, sacs and
clappers.
Para 2-3
main idea
Sound generation is complex: air through the right nasal
passage → the monkey lips → one air-filled s________
→ another sac through the s__________ o__________ →
fatty tissue → c__________ in the water
Four different clicks:
common ones -- long-range s__________
creaks -- p___________ capture
slow clicks -- maybe m_____________
Para 4-9
codas -- socializing
more details
Codas are of most scientific interest, because of its
functions:
1. d_________ between clan members
2. n__________ of individual whales
3. finding _________
food: j__________ squid; g_________ squid
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12.2 Test Questions
31. The main purpose of the passage is to:
A. describe how sperm whales use clicks to hunt their prey.
B. evaluate historical theories regarding sperm whale clicks.
C. provide details about the antagonism between sperm whales and squid.
A. explain how sperm whales generate and use clicks.
32. In the eighth paragraph(lines 74-77), the passage begins to focus on the relationship between:
F. squid and their prey.
G. sperm whales and sonar.
H. sperm whales and codas.
J. squid and sperm whales.
33. The main purpose of the second paragraph (lines 17-30) is to:
A. compare sperm whales to telegraph machines.
B. explain the function of the spermaceti organ.
C. outline how scientists came to understand the anatomy of the sperm whale.
D. describe the sperm whale anatomy involved in creating sound.
34. It can reasonably be inferred from the passage that codas are of particular interest because
scientists don't yet fully understand:
F. how codas help sperm whales hunt.
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G. how codas function in sperm whale socialization.
H. why codas are emitted only by male whales.
J. why codas are so difficult to detect.
35. As it is presented in the passage,the study that appeared in Animal Behaviour concluded that
sperm whale vocal clans:
A. each use a distinct dialect, and individuals within each clan have unique codas.
B. can adopt the codas of other clans, but individuals within each clan maintain unique dialects.
C. each use many dialects, and individuals within each clan develop complex codas.
D. can adopt the codas of other clans, but individuals within each clan retain unique identifiers.
36. The passage indicates that compared to the sounds beluga whales and humpback whales make,
the sounds sperm whales make are:
F. more complex and varied.
G. more frequent and melodic.
H. less elaborate and songlike.
J. less enigmatic and repetitive.
37. According to the passage, who confirmed the observation that sperm whales make loud
knocking noises?
A. Beale
B. Nineteenth-century whalers
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C. Woods Hole scientists
D. Whitehead
38. As it is used in line 25, the word runs most nearly means:
F. acts.
G. hastens.
H. operates.
J. leads.
39. Based on the passage, the notion that slow clicks are related to sperm whale mating behavior is
best described as a:
A. fact that is supported by several scientific studies.
B. fact that whalers discovered in the 1800s.
C. reasoned judgment from an expert in biology.
D. reasoned judgment from the passage author.
40. Which of the following statements about the mystery of how sperm whales locate squid is best
supported by the passage?
F. The mystery was solved in the 1800s.
G. The mystery was solved recently.
H. The mystery is likely to be solved in the near future.
J. The mystery is likely to remain unsolved until better technology is invented.
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本节内容回顾 Review
1. 精读文章时，须根据自然类文章的典型文章结构，构建出文章的
mindmap。
2. 科学家的研究或发现成果一般会考到，因此第一次看到某科学家
的名字时，highlight 出来。
3. 细节和例子一般也会考到，留意它们证明的是哪个观点或发现。
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第十三节 自然科学类--篇章精读 2
Unit 13 Natural Science--Intensive Reading 2
本节主要目标 Lesson Aim
通过精讲一篇经典的带实验类自然科学类文章，帮助你
1. 运用之前所学的阅读策略、自然科学知识来分析文章和考题，了
解和掌握实验类文章的考点；
2. 进一步熟悉自然科学类文章的一般结构和考点；
3. 掌握长难句和词汇。
Pre-learning Vocabulary
Vocabulary in the passage
Word
Part of
Phrase
Meaning
Word
Part of
speech
Phrase
speech
rewind
v
swirl
v
exhort
v
culture
n
stripped-down
adj
intrinsic
adj
play out
v phr
peer over
v phr
one’s
shoulders
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glucose
n
strain
n
mutation
n
randomness
n
Meaning
plateau
n
trajectory
n
lethal
adj
citrate
n
E. coli
n
contingent
adj
Word
Part of
* 单词的顺序按在 passage 里面出现的顺序。
Vocabulary in test questions
Word
Part of
Meaning
Phrase
speech
Phrase
speech
exhibit
v
striking
v
variation
n
refrain from
v phr
differ
v
outnumber
v
* 单词的顺序按在 test questions 里面出现的顺序。
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Meaning
Passage IV
NATURAL SCIENCE:This passage is adapted from the
article "Molecular Evolution" by Tina Hesman Saey
(© 2009 by Society for Science & the Public).
5
10
15
20
25
30
35
40
45
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Richard Lenski, an evolutionary biologist, is among
the scientists hitting the rewind button on evolution.
Meter-high letters taped to the window of his lab
spell out the lab's motto: EVOLVE.
1. What is the rhetorical function of the first
paragraph?
__________________________________________________________
__________________________________________________________
Inside the lab, a dozen glass flasks containing clear
liquid swirl in a temperature-controlled incubator.
Although the naked eye can't see them, millions of E.
coli bacteria grow in the flasks, doing what the
window exhorts. Lenski started the cultures in 1988,
intending to follow the course of natural selection for
several hundred generations. Now, two decades later,
the cultures are still growing and have produced
more than 45,000 generations of bacteria each.
2. Which purpose does Lenski’s experiment want to
achieve?
__________________________________________________________
__________________________________________________________
These 12 flasks "represent the stripped-down bare
essentials of evolution," says Zachary Blount, a
graduate student in Lenski's lab. The environment
never changes. No new genes enter the system from
migrating microorganisms. And the scientists take no
action to affect the course of evolution within the
flasks. Only the intrinsic, core processes of evolution
influence the outcome, Blount says.
3. What is the likely reason for the experiment design
that “No new genes enter the system from migrating
microorganisms”?
__________________________________________________________
__________________________________________________________
Lenski and his colleagues have watched the game
play out, occasionally analyzing DNA to peer over the
players' shoulders and find out what cards they hold.
On the surface, the populations in the 12 flasks seem
to have traveled similar paths—all now grow larger
cells and have become more efficient at using
glucose than their ancestors. And many of the strains
have accumulated mutations in the same genes.
Notably, though, none of the strains developed
exactly the same genetic changes.
4. What is the metaphorical meaning of expressions
“the game”, “peer over the players' shoulders” and
“what cards they hold”?
__________________________________________________________
__________________________________________________________
Randomness is an important part of the
evolutionary equation, as the experiment illustrates.
During the first 2,000 generations, all of the 12
populations rapidly increased in size and fitness. But
then these changes began to slow down, hitting the
evolutionary equivalent of a dieter's plateau.
5. Starting from this paragraph, the focus of the
passage shifts from introduction and experiment
design description to experiment procedures and
f__________________.
After 10,000 generations, it became apparent that
not all the flasks were on the same trajectory. Though
cells in all the flasks became larger, each population
differed in the maximum size the cells reached. The
populations also differed in how much fitter they
were than their ancestors, when grown in direct
competition. Several of the flasks now contain
mutator strains, bacteria that have defects in their
DNA replication system. Such defects make mistakes
6. Why does the author compare the changes to “a
dieter’s plateau” in line 37?
__________________________________________________________
7. Based on the description from line 38 to 69, fill in the
following blanks for what takes place during the
experiment.
Before 2,000 generations: ______________________________
__________________________________________________________
After 10,000 generations: ______________________________
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60
more likely to happen every time those bacterial
strains copy their DNA to divide, Sometimes a
mistake can have lethal consequences, damaging a
gene crucial for survival. But other times coloring a
bit outside the lines creates opportunity for
advancement.
__________________________________________________________
For more than 12,000 generations: ____________________
__________________________________________________________
After about 31,500 generations: _______________________
__________________________________________________________
Even within a given flask, some bacteria take
slightly different paths. One flask now contains two
separate strains — one that makes large colonies
when grown on petri dishes, and one that makes
small colonies. The large- and small-colony strains
have coexisted for more than 12,000 generations.
The large-colony producers are much better at using
glucose so they grow quickly, but they make
by-products that the small-colony producers can eat.
Both strains have increased in fitness over the
generations.
Still, though the details were different, replaying
evolution in a dozen flasks produced very similar
outcomes in each.
65
But then something completely unexpected
happened. After about 31,500 generations,
glucose-eating bacteria in one flask suddenly
developed the ability to eat a chemical called citrate,
something no other E. coli do.
70
The switch was clearly a radical change of
destination for the bacteria. The inability to eat
citrate is a bio-chemical hallmark of the E. coli
species, so by some definitions, the citrate eaters in
that flask are no longer E.coli.
8. What is the implied implication of “a radical
change” to evolution in line 70?
__________________________________________________________
__________________________________________________________
75
But a single change did not a citrate eater make.
The researchers found that the bacteria went through
a series of steps before evolving the ability to use
citrate. One initial mutation happened at least 11,000
generations before the citrate eaters appeared.
Lenski doesn't yet know which specific DNA changes
led to citrate use, but it's clear that the ability to use
citrate is contingent upon those earlier changes. And
even bacteria that have undergone those initial
changes are still not guaranteed to eat citrate. Blount
tested 40 trillion bacteria from earlier generations to
see if any could evolve the ability to eat citrate. Fewer
than one in a trillion could.
9. Why does the radical change take place?
__________________________________________________________
The profound difference between the citrate eaters
and the other 11 strains, as well as the dependence
of the citrate change on earlier mutations, seems to
suggest that replaying evolution will result in some
surprise endings.
10. What is the final conclusion drawn from the
experiment?
__________________________________________________________
__________________________________________________________
80
85
90
11
13.1 Reading Comprehension
Based on the above analysis, fill in the blanks to finish the mindmap of the passage.
Para1
background
Introduction of evolutionary biologist Richard Lenski
and his l_________________.
information
Experiment description:
E. coli bacteria grow by their own.
Purpose:
Researchers attempt to imitate the process of n________
s_____________.
Para 2-4
Experiment
Experiment design:
No new genes
No artificial a_____________
Only observe o_____________
Initially, cells in all flasks were on the same
Para 5-11
findings
t__________________________.
Then, they d__________ in both maximum size and fitness.
Later, they are different even in the same f_____________.
Finally, a new species evolved.
Para 12
conclusion
Redoing an evolutionary process may not get the same
end.
13.2 Test Questions
31. Based on the passage, which of the following statements best describes the evolution of
bacteria populations in the flasks?
A. Although most populations exhibited few evolutionary changes, one underwent a striking
11
transformation within the first 100 generations.
B. Although most populations followed the same evolutionary path, one produced bacteria that
consumed glucose.
C. Although the populations evolved differently at first, the populations became increasingly similar
after 2,000 generations.
D. Although not all of the populations followed the same evolutionary path, the outcomes were all
similar up to about 31,500 generations.
32. The passage indicates that the differences that have developed between the flask populations
are in part a result of:
F. temperature changes occurring within each flask.
G. random mutations occurring within each flask.
H. variations in the number of bacteria initially placed in each flask.
J. variations in the age of the populations initially placed in each flask.
33. When the author states the bacteria in the flasks are "doing what the window exhorts"(lines 8-9),
she most nearly means the bacteria are:
A. moving.
B. evolving.
C. swirling.
D. growing.
11
34. Based on the passage, Blount claims that the flasks "represent the stripped-down bare essentials
of evolution"(lines 14-15) due to which of the following conditions?
I. The bacteria in the flasks are maintained in a consistent, closed environment
II. No genes from migrating microorganisms enter the flasks.
III. Scientists refrain from actions that affect the course of evolution in the flasks.
F. I only
G. II only
H. III only
J. I, Il, and III
35. The main purpose of the seventh paragraph (lines 52-61) is to:
A. contrast the age of small-colony strains of bacteria with that of large-colony strains.
B. compare conclusions reached by Lenski's experiment to those reached by similar experiments.
C. offer an example of how bacterial strains grown within a single flask can differ.
D. suggest several conclusions scientists could draw by comparing the colonies within a given flask.
36. The passage suggests that some strains of bacteria produce larger colonies than do others
because the larger-colony strains:
F. use glucose more effectively.
G. eat the by-products of other colonies.
H. have fewer mutator genes in their DNA.
J. have coexisted with other strains for generations.
11
37. Based on the passage, what was the most surprising development observed during Lenski's
experiment?
A. Citrate eaters outnumbered the other eleven strains of bacteria after just two generations.
B.Bacteria in one flask divided into two separate strains.
C. Bacteria in one flask developed into a new species of citrate eaters.
D. Both large- and small-colony bacteria strains increased in fitness over 12,000 generations.
38. According to the passage, after 10,000 generations, one indication that bacteria were
developing differently in different flasks was that:
F. cells in each flask reached a different maximum size.
G. there were more cells in some flasks than in others.
H. some flasks produced new generations more quickly than did other flasks.
J. cells in some flasks began to die off at a quicker rate.
39. According to the passage, by some definitions, one characteristic of the E.coli species is its
inability to:
A. cat citrate.
B. consume glucose.
C. coexist with other types of bacteria.
D. duplicate its DNA.
11
40. As it is used in line 87, the word profound most nearly means:
F. perceptive.
G. extreme.
H. heartfelt.
J. difficult.
本节内容回顾 Review
1. 自然类文章的典型文章结构之一：introduction → experiment
purpose → experiment design → experiment procedures /
steps → findings → implications → limitations。
2. 自然科学文章里面也有 literary devices，也会是考点。
11
第十四节 自然科学类-双篇精读（上）
Unit 14 Natural Science--Paired Passages I
本节主要目标 Lesson Aim
通过精讲经典的自然科学类双篇文章，帮助你
1. 运用之前所学的阅读策略、自然科学知识来分析文章和考题；
2. 更熟练掌握自然科学类文章的一般结构和考点，了解自然科学双篇
文章的考点；
3. 掌握长难句和词汇。
Pre-learning Vocabulary
Word
Part of
Phrase
Meaning
Word
Part of
speech
Phrase
speech
striking
adj
neuron
n
von Economo
n
anatomist
n
spindle
n
empathy
n
sociality
n
puzzling
adj
disparate
adj
specialized
adj
primate
adj
lineage
n
cetacean
n
lie in
v phr
cortex
n
visceral
adj
cell
11
Meaning
bypass
v
anthropomorphism
n
pirate
n
hoist
v
perish
v
at stake
prep
attribute to
v phr
monopoly
n
absurdity
n
impose on
v phr
hamper
v
self-preservation
n
* 单词的顺序按在 passage 里面出现的顺序。
11
Passage IV
NATURAL SCIENCE: Passage A is from the book
Animal Wise: The Thoughts and Emotions of Our
Fellow Creatures by Virginia Morell. Passage B is from
the essay "Big Love: The Emotional Lives of
Elephants" by Carl Safina.
5
10
15
20
25
30
35
40
45
11
Passage A by Virginia Morell
One of the more striking discoveries in
neuro-science in recent years is the finding that
elephants, whales, great apes, and humans all possess a
peculiar kind of brain cell. These neurons were first
discovered in human brains in the nineteenth century
and were named von Economo cells after the
Romanian anatomist Constantin von Economo, who
identified them. At first, these spindle-shaped neurons were
touted as the cells that "make us human," because they're
connected to our feelings of empathy, love, emotional
suffering, and sociality. Then, in 1999, two other
researchers, Patrick Hof and John Allman, spotted
von Economo cells in the brains of all the great apes;
others recently found them in monkeys. Allman has
searched without luck for the cells in more than a
hundred other species, from sloths to platypuses. So
it was big news when, in 2007, he discovered spindle
cells in the brains of whales, dolphins, and elephants.
But it was a puzzling discovery, too. Why should such
a disparate group of animals have these specialized cells?
1. What is the new scientific discovery?
__________________________________________________________
__________________________________________________________
2. What was the original value of the von Economo
cells discovery? How did the value change?
__________________________________________________________
__________________________________________________________
3. What is the rhetorical purpose of the question at the
end of the first paragraph?
__________________________________________________________
__________________________________________________________
From an evolutionary point of view, it's not
surprising that primates and humans have von
Economo cells, since we are in the same lineage. But
primates and humans haven't shared an ancestor
with whales or elephants since about the beginning
of the mammalian lineage, some sixty million years
ago. It seems that cetaceans and elephants evolved
their spindle cells independently. What factors would
produce such emotionally specialized brain cells?
4. Based on the whole passage, what is the function of
the second paragraph?
__________________________________________________________
__________________________________________________________
Allman thinks part of the answer lies in the size of
the animals' brains—most species that have spindle
cells also have notably large brains — and in the
location of the cells. Von Economo cells are always
found in two regions of the cortex associated with
emotionally charged, visceral judgments, such as
deciding whether a fellow animal is suffering. And
part of the answer lies in the size of the spindle cells.
They are unusually large, enabling them to act like
high-speed circuits, fast-tracking information to and
from other parts of the brain, while bypassing
unnecessary connections. These are the kind of cells,
Allman argues, that would be especially useful to an
animal living in a complex society—a society in which
making accurate, intuitive decisions about another's
actions (or facial or vocal expressions) is crucial for
your family's and your survival.
5. According to Allman, what is the reason for the
phenomenon that different species of animals to have
von Economo cells?
__________________________________________________________
__________________________________________________________
6. What is the true value of von Economo cells?
__________________________________________________________
__________________________________________________________
Passage B by Carl Safina
Anthropomorphism is the attribution of human
motivation, characteristics, or behavior to animals,
inanimate objects, or natural phenomena.
50
55
60
65
70
75
80
85
In establishing the study of animal behavior as a
science, it had originally been helpful to make
anthropomorphism a word that raised a red flag. But
as lesser intellects followed the Nobel Prize-winning
pioneers, anthropomorphism became a pirate flag. If
the word was hoisted, an attack was imminent. You
wouldn't get your work published. And in the
academic realm of publish or perish, jobs were at
stake. Even the most informed, insightful, logical
inferences about other animals' motivations, emotions, and
awareness could wreck your professional prospects.
7. What is the scientific problem described in the first
paragraph?
__________________________________________________________
__________________________________________________________
But what is a "human" emotion? When someone
says you can't attribute human emotions to animals,
they forget the key leveling detail: humans are
animals. Human sensations are animal sensations.
Inherited sensations, using inherited nervous systems.
9. Why does the author use quotation marks here?
__________________________________________________________
__________________________________________________________
All of the emotions we know of just happen to be
emotions that humans feel. So, simply deciding that
other animals can't have any emotions that humans
feel is a cheap way to get a monopoly on all of the
world's feelings and motivation. People who've
systematically watched or known animals realize the
absurdity of this. But many others still don't. "The
dilemma remains," wrote author Caitrin Nicol
recently, "how to get an accurate understanding of
the animals' nature and (if appropriate) emotions,
without imposing on them assumptions born of a
distinctly human understanding of the world."
But tell me, what "distinctly human understanding"
hampers our understanding of other animals'
emotions? Is it our sense of pleasure, pain, hunger,
frustration, self-preservation, defense, parental
protection? We never seem to doubt that an animal
acting hungry feels hungry. What reason is there to
disbelieve that an elephant who seems happy is
happy? We can't really claim scientific objectivity
when we recognize hunger and thirst when animals
are eating and drinking, exhaustion when they tire, but deny
them joy and happiness as they're playing with their children
and their families. Yet the science of animal behavior has
long operated with that bias—and that's unscientific. In
science, the simplest interpretation of evidence is often the
best.
14.1 Reading Comprehension
12
8. Based on the whole passage, what is the function of
the first paragraph?
__________________________________________________________
__________________________________________________________
10. For what purpose is Caitrin Nicol quoted?
__________________________________________________________
__________________________________________________________
11. What is the purpose of rhetorical questions in the
last paragraph?
__________________________________________________________
__________________________________________________________
Based on the above analysis, fill in the blanks to finish the mindmap of the passage.
Passage A
Background: spindle cells were believed to make us
“h_____________.”
Para1
background
information
new discovery: the cells are also found in other animals
+ new discovery
such as d_____________ and e_____________.
Reason 1: primates and humans share the same a_______.
Refuted: primates and humans don’t have the same
lineage as c___________, in which the cells are also found.
Para 2-3
possible reasons
Reason 2: the size of the animals' b__________; the
l_____________ of the cells; the s____________ of the cells.
Implication: the cells help s____________ of animals and
their families.
Passage B
Para1
Background: it was h____________ that
anthropomorphism raised a red flag.
background
information
+scientific problem
Scientific problem: but this becomes a serious problem
in the a____________ r____________ .
Counterargument: You can't a____________ human
emotions to animals.
Refutation 1: humans are animals.
Refutation 2: a m____________ on emotions;
Para 2-4
Counter-argument
+ refutations
a___________
Refutation 3: It is u____________ to deny animals’
Evidence: quote from author Caitrin Nicol
feelings.
Evidence: facts that animals have the same feelings
as humans, such as h_______, t______, joy and happiness.
12
第十五节 自然科学类-双篇精读（下）
Unit 15 Natural Science--Paired Passages II
本节主要目标 Lesson Aim
通过精讲经典的自然科学类双篇文章，帮助你
1. 运用之前所学的阅读策略、自然科学知识来分析文章和考题；
2. 更熟练掌握自然科学类文章的一般结构和考点，了解自然科学双篇
文章的考点；
3. 掌握长难句和词汇。
Pre-learning Vocabulary
Word
Part of
Phrase
Meaning
Word
Part of
speech
Phrase
speech
lineage
n
correlation
n
cortex
n
ambivalent
adj
necessarily
adv
interfere with
v phr
assess
v
neuroscience
n
drive
n
anecdotal
adj
extensive
adj
bluntly
adv
ground
v
hands-on
adj
* 单词的顺序按在 test questions 里面出现的顺序。
12
Meaning
Test Questions
Questions 31-34 ask about Passage A.
31. Passage A most strongly suggests that in the nineteenth century, anatomists generally believed:
A. our feelings of empathy, love, and sociality weren't part of what makes us human.
B. von Economo cells existed only in the human brain.
C. the spindle-shaped neurons that von Economo identified shouldn't be named for him.
D. it was crucial to search for von Economo cells in a variety of animals.
32. It can most reasonably be inferred from Passage A that Allman's search for von Economo cells in
which of the following animals occurred last chronologically?
F. Sloths
G. Dolphins
H. Platypuses
J. Great apes
33. The main point of the second paragraph of Passage A (lines 21-29) is that:
A. at the beginning of the mammalian lineage, primates and humans shared ancestors with whales
and elephants.
B. primates and humans are in the same lineage.
C. some animals seem to have been able to develop von Economo cells independently from
primates and humans.
D. von Economo cells can be described as "emotionally specialized brain cells."
12
34. According to Passage A, Allman believes a clear correlation exists between a species having
spindle cells and that species having:
F. a close genetic link to whales.
G. several types of neurons.
H. a very large brain.
J. a Cortex.
Questions 35-37 ask about Passage B.
35. Based on Passage B, how does the passage author feel about the trend in the academic study of
animal behavior that is described in lines 49-57?
A. He strongly disapproves.
B. He is ambivalent.
C. He reluctantly approves.
D. He enthusiastically approves.
36. Based on the last paragraph of Passage B, which of the following statements would be the
clearest example of "the simplest interpretation of evidence"(line 88)?
F. Parental protection is the most advanced and humanlike emotion that animals can feel.
G. When animals seem frustrated in a frustrating context, the animals are feeling frustration.
H. An animal that seems hungry might not necessarily be hungry.
J. Humans' own emotions interfere with the ability to assess emotion in animals.
12
37. The author of Passage B criticizes the conclusion that if humans feel a particular emotion, then
animals:
A. won't be able to recognize that emotion in humans.
B. will want to learn how to have that emotion.
C. can't have that emotion.
D. must have that emotion.
Questions 38-40 ask about both passages.
38. Which of the following statements best captures a key difference in the way the passages
explore the link between human and animal emotions?
F. Passage A focuses on neuroscience, whereas Passage B focuses on the observation of behavior.
G. Passage A focuses on nineteenth-century research, whereas Passage B focuses on current
research.
H. Passage A focuses on survival drives, whereas Passage B focuses on familial bonds.
J. Passage A focuses on anecdotal evidence, whereas Passage B focuses on one extensive study.
39. Which of the following statements best captures one difference in the purposes of Passage A
and Passage B?
A. Passage A aims to bluntly correct readers' assumptions, while Passage B aims to confirm readers'
assumptions.
B. Passage A aims to urge readers to action, while Passage B aims to encourage readers to stop
12
acting carelessly.
C. Passage A aims to present two opposing viewpoints for readers to evaluate, while Passage B aims
to entertain readers.
D. Passage A aims to inform readers about a recent finding, while Passage B aims to challenge
readers with a bold argument.
40. The passages provide the clearest evidence that which of the following people performs work
that is grounded in hands-on scientific research?
F. The author of Passage A
G. The author of Passage B
H. Allman, as he is presented in Passage A
J. Nicol, as she is presented in Passage B
本节内容回顾 Review
1. 自然科学文双篇之间的关系可能包括：
立场_____________
立场_____________
立场_____________（同一___________，不同___________）
2. 自然科学类文章也可能有较难的篇章，例如本节的 Passage B
（__________________________使用较多，_____________的思考），值得
多精读，习惯其写作的风格。
12
章节测试 3
NATURAL SCIENCE: This passage is adapted from Last
Discoveries: The Ancient Roots of Modern Science
from the Babylonians to the Maya by Dick
Teresi(©2002 by Dick Teresi)
5
Antoine-Laurent Lavoisier (1743-1794) was a
financier, established a system of weights and
measures that led to the metric system, lived through
the early turmoil of the French Revolution, and was a
pioneer in scientific agriculture. He has been called
the father of modern chemistry, and, in the course of
his busy life, he brought Europe out of the dark ages
of that science.
45
50
55
10
15
20
25
30
35
40
12
One of Lavoisier's early contributions resulted from
his boiling water for long periods of time. In
eighteenth-century Europe, many scientists believed
in transmutation. They thought, for instance, that
water could be transmuted into earth, among other
things. Chief among the evidence for this was water
boiling in a pot. Solid residue forms on the inside
surface, Scientists proclaimed this to be water turning
into a new element. Robert Boyle, the great
seventeenth-century British chemist and physicist
who flourished a hundred years before Lavoisier,
believed in transmutation. Having watched plants
grow by soaking up water, he concluded, as many had
before him, that water can be transformed into leaves,
flowers, and berries. In the words of chemist Harold
Goldwhite, of California State University, Los Angeles,
"Boyle was an active alchemist."
Lavoisier noticed that weight was the key, and that
measurement was critical. He poured distilled water
into a special "tea kettle" called a pelican, an enclosed
pot with a spherical cap, which caught the water
vapor and returned it to the base of the pot via two
handlelike tubes. He boiled the water for 101 days
and found substantial residue, He weighed the water,
the residue, and the pelican, The water weighed
exactly the same. The pelican weighed slightly less, an
amount equal to the weight of the residue. Thus, the
residue was not a transmutation, but part of the pot
—dissolved glass, silica, and other matter.
As scientists continued to believe that water was a
basic element, Lavoisier performed another crucial
experiment. He invented a device with two nozzles
and squirted different gases from one into the other,
to see what they made. One day, he mixed oxygen
with hydrogen, expecting to get acid. He got water.
He percolated the water through a gun barrel filled
60
65
70
75
80
85
with hot iron rings, splitting the water back into hydrogen
and oxygen and confirming that water was not an element.
Lavoisier measured everything, and on each
occasion that he performed this experiment, he got
the same numbers. Water always yielded oxygen and
hydrogen in a weight proportion of 8 to 1. What
Lavoisier saw was that nature paid strict attention to
weight and proportion. Ounces or pounds of matter
did not disappear or appear at random, and the same
ratios of gases always yielded the same compounds,
Nature was predictable ... and therefore malleable.
Ancient Chinese alchemy, circa 300 to 200 B.C, was
built around the concept of two opposing principles.
These could be, for example, active and passive, male
and female, or sun and moon. The alchemists saw
nature as having a circular balance. Substances could
be transformed from one principle to another, and
then rendered back to their original state.
A prime example is cinnabar, known commonly
today as mercuric sulfide, a heavy red mineral that is
the principal ore of mercury. Using fire, these early
alchemists decomposed cinnabar into mercury and
sulfur dioxide. Then they found that mercury would
combine with sulfur to form a black substance called
metacinnabar, "which then can be sublimed into its
original state, the bright red cinnabar, when once
more heated," according to science historian Wang
Kuike. Both mercury's liquid quality and the cyclic
transformation from cinnabar to mercury and back
again gave it magical qualities. Kuike calls mercury
"huandan, a cyclically transformed regenerative elixir"
associated with longevity. These ancient practitioners
became familiar with the concept that substances
could be transformed and then come full circle to
their original state. They developed exact proportions
of the amounts of mercury and sulfur, as well as
recipes for the exact length and intensity of the
heating required. Most important, according to Kuike,
these operations could be performed "without the
slightest loss of the total weight."
It would appear that the ancient Chinese alchemists
were empirically familiar with the conservation of
mass fifteen hundred years before Lavoisier's
experiment. He and his alchemist precursors
discovered that the weight of the products in a
chemical reaction equal the weight of the reactants.
1. In the sixth paragraph(lines 55-61), the focus of the passage shifts from a discussion of:
A. Lavoisier's system of weights and measures to a description of ancient Chinese measurement
systems.
B. the findings of European alchemists to an explanation of how ancient Chinese alchemy
undermined these findings.
C. some of Lavoisier's most important scientific findings to a discussion of similar, earlier findings in
China.
D. Boyle's influence on Lavoisier's work to a discussion of how Chinese alchemists influenced
Lavoisier's work.
12. One of the main purposes of the passage is to:
F. provide a historical overview of how alchemy evolved.
G. highlight scientific experiments that prove that mass is always conserved.
H. demonstrate how ancient Chinese science experiments inform studies in science today.
J. describe the importance of a few chemical elements in famous historical experiments.
3. The passage suggests that, regarding the method Lavoisier used to conduct his experiments,
what was most critical was:
A. using the most accessible chemical elements.
B. inventing the equipment to use in his experiments.
C. consulting the research of his contemporaries.
D. ensuring precise measurements.
12
4. Based on the passage, Lavoisier's hydrogen-and-oxygen experiment and the ancient Chinese
cinnabar experiment have in common the fact that they both:
F. disproved earlier scientific theories about weight and proportion.
G. involved minerals associated with longevity.
H. transformed substances to different forms and then back to their original states.
J. required specially designed equipment.
5. The main purpose of the first paragraph is to introduce Lavoisier by:
A. noting his varied accomplishments and historical importance.
B. describing his contributions to science and the French Revolution.
C. subtly questioning his title as the father of modern chemistry.
D. suggesting that his pioneering work in scientific agriculture brought Europe out of the Dark Ages.
6. The main idea of the second paragraph (lines 8-24) is that:
F. in the eighteenth century. Boyle and Lavoisier were leading scientists who made significant
contributions to alchemy.
G. Lavoisier hypothesized that boiled water would transmute into a new clement.
H. Boyle developed the theory of transmutation after watching plants soak up water and grow
leaves, flowers, and berries.
J. transmutation was a long-held theory that, among other things, explained why residue remained
in a pot after boiling water.
12
7. It can logically be concluded that Lavoisier's hydrogen-and-oxygen experiment was "crucial" (line
38)mainly because it:
A. was the first to mix naturally occurring elements.
B. refuted an established scientific belief.
C. introduced new methods of measurement.
D. led to the invention of a device used in other experiments.
8. As it is used in line 14, the word forms most nearly means:
B. constitutes.
C. models.
H. arranges.
J. accumulates.
9. According to the passage, when Lavoisier first mixed oxygen with hydrogen, he expected to get:
A. water.
B. acid.
C. vapor.
D. sulfur.
10. The example of the sun and moon in the passage helps illustrate the point that Chinese
alchemists:
13
F. focused on the concept of two opposing principles.
G. were some of the earliest scientific practitioners.
H. often transformed substances from one principle to another.
J. believed nature was predictable and malleable.
Vocabulary Review
Vocabulary in the passage
Word
Part of
Phrase
Meaning
Word
Part of
speech
Phrase
speech
Babylonian
adj
turmoil
n
transmutation
n
residue
n
proclaim
v
alchemist
n
spherical
adj
dissolved
adj
silica
n
nozzle
n
squirt
v
percolate
v
split
v
yield
v
compound
n
malleable
adj
alchemy
n
mercuric
n phr
sulfide
13
principal
adj
ore
n
decompose
v
sublime
v
Meaning
elixir
n
empirically
adv
elixir
precursor
n
reactant
n
precursor
Word
Part of
Meaning
* 单词的顺序按在 passage 里面出现的顺序。
Vocabulary in test questions
Word
Part of
Meaning
Phrase
speech
Phrase
speech
sloth
n
platypuse
n
undermine
v
overview
n
conserve
v
accessible
adj
contemporary
n
longevity
n
established
adj
constitute
v
sulfur
n
practitioner
n
* 单词的顺序按在 test questions 里面出现的顺序。
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