Reading
*Planet Jupiter
5
10
15
20
Europa is the smallest of planet Jupiter’s four largest moons and the second moon out
from Jupiter. Until 1979, it was just another astronomy textbook statistic. Then came the closeup images obtained by the exploratory spacecraft Voyager 2, and within days, Europa was
transformed-in our perception, at least-into one of the solar system’s most intriguing worlds.
The biggest initial surprise was the almost total lack of detail, especially from far away. Even
at close range, the only visible features are thin, kinked brown lines resembling cracks in an
eggshell. And this analogy is not far off the mark.
The surface of Europa is almost pure water ice, but a nearly complete absence of craters
indicates that Europa’s surface ice resembles Earth’s Antarctic ice cap. The eggshell analogy
may be quite accurate since the ice could be as little as a few kilometers thick –a true shell
around what is likely a subsurface liquid ocean that , in turn, encases a rocky core. The interior
of Europa has been kept warm over the eons by tidal forces generated by the varying
gravitational tugs of the other big moons as they wheel around Jupiter. The tides on Europa
pull and relax in an endless cycle. The resulting internal heat keeps what would otherwise be
ice melted almost to the surface. The cracklike marks on Europa’s icy face appear to be
fractures where water or slush oozes from below.
Soon after Voyager 2’s encounter with Jupiter in 1979, when the best images of Europa
were obtained, researchers advanced the startling idea that Europa’s subsurface ocean might
harbor life. Life processes could have begun when Jupiter was releasing a vast store of internal
heat. Jupiter’s early heat was produced by the compression of the material forming the giant
planet. Just as the Sun is far less radiant today than the primal. Sun, so the internal heat
generated by Jupiter is minor compared to its former intensity. During this warm phase, some
4.6 billion years ago, Europa’s ocean may have been liquid right to the surface, making it a
crucible for life.
1. What does the passage mainly discuss?
(A) The effect of the tides on Europa’s interior
(B) Temperature variations on Jupiter’s moons
(C) Discoveries leading to a theory about one of Jupiter’s moons
(D) Techniques used by Voyager 2 to obtain close-up images.
2. The word “intriguing” in line 4 is closest in meaning to
(A) changing
(B) perfect
(C) visible
(D) fascinating
3. In line 7, the another mentions “cracks in an eggshell” in order to help readers
(A) visualize Europa as scientists saw it in the Voyager 2 images
(B) appreciate the extensive and detailed information available by viewing Europa from
far away
(C) understand the relationship of Europa to the solar system
(D) recognize the similarity of Europa to Jupiter’s other moons
4. It can be inferred from the passage that astronomy textbooks prior to 1979
(A) provided many contradictory statistics about Europa
(B) considered Europa the most important of Jupiter’s moons
(C) did not emphasize Europa because little information of interest was available
(D) did nor mention Europa because it had not yet been discovered
5. What does the author mean by stating in line 7 that “this analogy is not far off the
mark”?
(A) The definition is not precise.
(B) The discussion lacks necessary information.
(C) The differences are probably significant.
(D) The comparison is quite appropriate
6. IT can be inferred from the passage that Europa and Antarctica have in common which
of the following?
(A) Both appear to have a surface with many craters.
(B) Both may have water beneath a thin, hard surface.
(C) Both have an ice can that is melting rapidly.
(D) Both have areas encased by a rocky exterior.
7. The word “endless” in line 14 is closest in meaning to
(A) new
(B) final
(C) temporary
(D) continuous
8. According to the passage, what is the effect of Jupiter’s other large moons on Europa?
(A) They prevent Europa’s subsurface waters from freezing.
(B) They prevent tides that could damage Europa’s surface.
(C) They produce the very hard layer of ice that characterizes Europa.
(D) They assure that the gravitational pull on Europa is maintained at a steady level.
9. According to the passage, what is believed to cause the thin lines seen on Europa’s
surface?
(A) A long period of extremely high tides
(B) Water breaking through from beneath the surface ice
(C) The continuous pressure of slush on top of the ice
(D) Heat generated by the hot rocky core
Archaelogical ( pot )
Archaeological literature is rich in descriptions of pot making. Unlike modern
industrial potters, prehistoric artisans created each of their pieces individually, using the
simplest technology but demonstrating remarkable skill in making and adorning their vessels.
The clay used in prehistoric pot making was invariably selected with the utmost care:
5
10
15
20
25
often it was traded over considerable distances. The consistency of the clay was crucial: it
was pounded meticulously and mixed with water to make it entirely even in texture. By careful
kneading, the potter removed the air bubbles and made the clay as plastic as possible, allowing
it to be molded into shape as the pot was built up, When a pot is fired. It loses its water and
can crack, so the potter added a temper to the clay, a substance that helped reduce shrinkage
and cracking.
Since surface finishes provided a pleasing appearance and also improved the durability
in day-to-day use, the potter smoothed the exterior surface of the pot with wet hands. Often a
wet clay solution, known as a slip, was applied to the smooth surface. Brightly colored slips
were often used and formed painted decorations on the vessel. In later times. Glazes came into
use in some areas. A glaze is a form of slip that turns to a glasslike finish during hightemperature firing. When a slip was not applied, the vessel was allowed to dry slowly until the
external surface was almost like leather in texture. It was then rubbed with a round stone or
similar object to give it a shiny, hard surface. Some pots were adorned with incised or stamped
decorations.
Most early pottery was then fired over open hearths. The vessels were covered with
fast-burning wood; as it burned, the ashes would all around the pots and bake them evenly
over a few hours. Far higher temperatures were attained in special ovens, known as kilns,
which would not only bake the clay and remove its plasticity, but also dissolve carbons and
iron compounds. Kilns were also used for glazing, when two firings were needed, Once fired,
the pots were allowed to cool slowly, and small cracks were repaired before they were ready
for
use.
1. What does the passage mainly discuss?
(A) Why archaeologists study prehistoric pot making
(B) How early pottery was made and decorated
(C) The development of kilns used by early potters
(D) The variety of decorations on Prehistoric pottery
2. The word “ meticulously” in line 7 is closest in meaning to..
A. Heavily
B. initially
C. carefully
D. completely
3. Which of the following was a process used by prehistoric potters to improve the
texture of the clay?
A. Adding temper
B. Removing the water
C. Beating on the clay
C. Mixing the clay with plastic substances
4.
The word “durability” in line 13 is closest in meaning to..
(A) Quality
(B) endurance
(C) adaptability
(D) applicability
5. Prehistoric potters applied slips and glazes to their vessels in order to do which of
the following?
A. Improve the appearance of the vessels
B. prevent the vessels from leaking
C. Help the vessels a leather like quality
D. Give the vessels a leather like quality
6. Which of the following was a method used by some potters to give vessels a glossy
finish?
A. Smoothing them with wet hands
B. Mixing the clay with colored solutions
C. Baking them at a very high temperature
D. Rubbing them with a smooth hard object
7.
The word “incised” in line 20 is closest in meaning to
(A)
8.
Designed (B) carved (C) detailed (D) painted
The word “they” in ling 26 refers to
(A) Kilns
(B) firings
(C) pots
(D) cracks
9.
According to the passage, the advantage of kilns over open fires was that the kilns
A. required less wood for burning
B. reached higher temperatures
C. kept ashes away from the pots
D. baked vessels without cracking them
10. Look at the terms “temper” (line 10), “glazes” (line 16), “kilns” (line 25), and
“compounds” (line 25). Which of these terms is NOT defined in the passage?
(A) Temper (B) glazes (C) kilns (D) compounds
11. The passage mentions that when pottery is fired under burning wood ,the ashes help
A. prevent the clay from cracking
B. produce a more consistently baked pot
C. attain a very high temperature
D. give the vessel a glasslike finish
Paleoanthropological
One area of paleoanthropological study involves the eating and dietary habits of
hominids, erect bipedal primates—including early humans. It is clear that at some stage of
history, humans began to carry their food to central places, called home bases, where it was
shared and consumed with the young and other adults. The use of home bases is a fundamental
5 component of human social behavior; the common meal served at a common hearth is a
5
powerful symbol, a mark of social unity.
Home base behavior does not occur among nonhuman primates and is rare among
mammals. It is unclear when humans began to use home bases, what kind of communications
and social relations were involved, and what the ecological and food-choice contexts of the
10 shift were. Work on early tools, surveys of paleoanthropological sites, development and
5
testing of broad ecological theories, and advances in comparative primatology are contributing
5
to knowledge about this central chapter in human prehistory.
One innovative approach to these issues involves studying damage and wear on stone
tools. Researchers make tools that replicate excavated specimens as closely as possible and
15 then try to use them as the originals might have been used, in woodcutting, hunting, or
5
cultivation. Depending on how the tool is used, characteristic chippage patterns and
5
microscopically distinguishable polishes develop near the edges. The first application of this
method of analysis to stone tools that are 1.5 million to 2 million years old indicates that, from
the start, an important function of early stone tools was to extract highly nutritious food—meat
20 and marrow-from large animal carcasses.
5
Fossil bones with cut marks caused by stone tools have been discovered lying in the
same 2-million-year-old layers that yielded the oldest such tools and the oldest hominid
specimens (including humans) with larger than ape-sized brains. This discovery increases
scientists' certainty about when human ancestors began to eat more meat than present-day
primates. But several questions remain unanswered: how frequently meat
25 nonhuman
eating occurred; what thesocial implications of meat eating were; and whether the increased
5
use of meat coincides with the beginnings of the use of home bases.
5
5
1. The passage mainly discusses which of the following aspects of hominid
behavior?
A. Changes in eating and dietary practices
B. The creation of stone hunting tools
C. Social interactions at home bases
D. Methods of extracting nutritious food from carcasses
2. According to the passage, bringing a meal to a location to be shared by many
individuals is
A. an activity typical of nonhuman primates
B. a common practice among animals that eat meat
C. an indication of social unity.
D. a behavior that encourages better dietary habits
3. The word "consumed" in line 4 is closest in meaning to
A. prepared
B. stored
C. distributed
D. eaten
4. According to paragraph 2, researchers make copies of old stone tools in order
to
A. protect the old tools from being worn out
B. display examples of the old tools in museums
C. test theories about how old tools were used
D. learn how to improve the design of modern tools
5. In paragraph 2, the author mentions all of the following as examples of
ways in which early stone tools were used EXCEPT to..
A. build home bases
B. obtain food
C. make weapons
D. shape wood
6. he word "innovative" in line 13 is closest in meaning to
A. good
B. new
C. simple
D. costly
7.
The word "them" in line 15 refers to
A. issues
B. researchers
C. tools
D. specimens
8.
The author mentions "characteristic chippage patterns" in line 16 as an
example of
A. decorations cut into wooden objects
B. differences among tools made of various substances
C. impressions left on prehistoric animal bones
D. indications of wear on stone tools
9.
10.
The word "extract" in line 19 is closest in meaning to..
A. identify
B. remove
C. destroy
D. compare
The word "whether" in line 26 is closest in meaning to
A. If
B. how
C. why
D. when
North America ( cooking / Oven )
5
5
5
10
5
5
In seventeenth-century colonial North America, all day-to-day cooking was done in
the fireplace. Generally large, fireplaces were planned for cooking as well as for warmth. Those
in the Northeast were usually four or five feet high, and in the South, they were often high
enough for a person to walk into. A heavy timber called the mantel tree was used as a lintel to
support the stonework above the fireplace opening. This timber might be scorched
occasionally, but it was far enough in front of the rising column of heat to be safe from catching
fire.
Two ledges were built across from each other on the inside of the chimney. On these
rested the ends of a "lug pole" from which pots were suspended when cooking. Wood from a
freshly cut tree was used for the lug pole, so it would resist heat, but it had to be replaced
frequently because it dried out and charred, and was thus weakened. Sometimes the pole broke
and the dinner fell into the fire. When iron became easier to obtain, it was used instead of wood
for lug poles, and later fireplaces had pivoting metal rods to hang pots from.
Beside the fireplace and built as part of it was the oven. It was made like a small,
15 secondary fireplace with a flue leading into the main chimney to draw out smoke. Sometimes
5
the door of the oven faced the room, but most ovens were built with the opening facing into
5
the fireplace. On baking days (usually once or twice a week) a roaring fire of "oven wood,"
consisting of brown maple sticks, was maintained in the oven until its walls were extremely
hot. The embers were later removed, bread dough was put into the oven, and the oven was
20 sealed shut until the bread was fully baked.
5
5
Not all baking was done in a big oven, however. Also used was an iron "bake kettle,"
which looked like a stewpot on legs and which had an iron lid. This is said to have worked well
when it was placed in the fireplace, surrounded by glowing wood embers, with more embers
piled on its lid.
1.
Which of the following aspects of domestic life in colonial North America
does the passage mainlydiscuss?
A. Methods of baking bread
B. Fireplace cooking
C. The use of iron kettles in a typical kitchen
D. The types of wood used in preparing meals
2.
The author mentions the fireplaces built in the South to illustrate
(A) how the materials used were similar to the materials used in northeastern
fireplaces
(B) that they served diverse functions
(C) that they were usually larger than northeastern fireplaces
(D) how they were safer than northeastern fireplaces
3.
The word "scorched" in line 5 is closest in meaning to
(A) burned
(B) cut
(C) enlarged
(D) bent
4.
The word "it" in line 6 refers to
(A) the stonework
(B) the fireplace opening
(C) the mantel tree
(D) the rising column of heat
5.
6.
7.
According to the passage, how was food usually cooked in a pot in the seventeenth
century?
(A) By placing the pot directly into the fire
(B) By putting the pot in the oven
(C) By filling the pot with hot water
(D) By hanging the pot on a pole over the fire
The word "obtain" in line 12 is closest in meaning to
(A) maintain (B) reinforce
(C) manufacture
(D) acquire
Which of the following is mentioned in paragraph 2 as a disadvantage of using a
wooden lug pole?
(A) It was made of wood not readily available.
(B) It was difficult to move or rotate.
(C) It occasionally broke.
(D) It became too hot to touch.
8.
9.
It can be inferred from paragraph 3 that, compared to other firewood, "oven wood"
produced
(A) less smoke (B) more heat
(C) fewer embers (D) lower flames
According to paragraph 3, all of the following were true of a colonial oven EXCEPT:
(A) It was used to heat the kitchen every day.
(B) It was built as part of the main fireplace.
(C) The smoke it generated went out through the main chimney.
(D) It was heated with maple sticks.
10. According to
the passage, which of the following was an advantage of a "bake kettle"?
(A) It did not take up a lot of space in the fireplace.
(B) It did not need to be tightly closed.
(C) It could be used in addition to or instead of the oven.
(D) It could be used to cook several foods at one time.
United States ( Ubranization )
5
5
5
Matching the influx of foreign immigrants into the larger cities of the United States
during the late nineteenth century was a domestic migration, from town and farm to city, within
the United States. The country had been overwhelmingly rural at the beginning of the century,
with less than 5 percent of Americans living in large towns or cities. The proportion of urban
population began to grow remarkably after 1840, increasing from 11 percent that year to 28
percent by 1880 and to 46 percent by 1900. A country with only 6 cities boasting a population
of more than 8,000 in 1800 had become one with 545 such cities in 1900. of these, 26 had a
population of more than 100,000 including 3 that held more than a million people.
Much of the migration producing an urban society came from smaller towns within the
10 United States, but the combination of new immigrants and old American "settlers" on
5
America's "urban frontier" in the late nineteenth century proved extraordinary. The growth of
5
cities and the process of industrialization fed on each other. The agricultural revolution
stimulated many in the countryside to seek a new life in the city and made it possible for fewer
farmers to feed the large concentrations of people needed to provide a workforce for growing
15 numbers of factories.
5
5
20
5
5
Cities also provided ready and convenient markets for the products of industry, and
huge contracts in transportation and construction-as well as the expanded market in consumer
goods-allowed continued growth of the urban sector of the overall economy of the Untied
States.Technological developments further stimulated the process of urbanization. One
example is the Bessemer converter (an industrial process for manufacturing steel), which
provided steel girders for the construction of skyscrapers. The refining of crude oil into
kerosene, and later the development of electric lighting as well as of the telephone, brought
additional comforts to urban areas that were unavailable to rural Americans and helped attract
many of them from the farms into the cities. In every era the lure of the city included a major
25 psychological element for country people; the bustle and social interaction of urban life seemed
5
particularly intriguing to those raised in rural isolation.
5
1.
What aspects of the United States in the nineteenth century does the passage mainly
discuss?
(A) Technological developments
(B) The impact of foreign immigrants on cities
(C) Standards of living
(D) The relationship between industrialization and urbanization
2.
The word "influx" in line 1 is closest in meaning to..
(A) working
3.
(B) processing
(C) arrival (D) attraction
The paragraph preceding the passage most probably discuss
(A) foreign immigration
(B) rural life
(C) the agricultural revolution
(D) famous cities of the twentieth century
4.
What proportion of population of the United States was urban in 1900?
(A) Five percent
(B) Eleven percent
(C) Twenty-eight percent
(D) Forty-six percent
5.
The word "extraordinary" in line 11 is closet in meaning to..
(A) expensive
(B) exceptional
(C) supreme
(D) necessary
The phrase "each other" in line 12 refers to..
6.
(A) foreign immigrants and domestic migrants
(B) farms and small towns
(C) growth of cities and industrialization
(D) industry and transportation
The word "stimulated" in line 13 is closest in meaning to..
7.
(A) forced (B) prepared (C) limited
(D)motivated
Why does the author mention "electric lighting" and "the telephone" in lines 22?
8.
(A) They contributed to the agricultural revolution
(B) They are examples of the conveniences of city life
(C) They were developed by the same individual.
(D) They were products of the Bessemer converter.
9.
The word "them" in line 24 refers to
(A) urban areas (B) rural Americans (C) farms
10.
The word "era" in line 24 is closest in meaning to
(A) period of time
11.
(D) cities
(B) location
(C) action
(D) unique situation
The word "intriguing" in line 26 is closest in meaning to
(A) profitable
(B) attractive (C) comfortable
(D) challenging
Glass
Glass is a remarkable substance made from the simplest raw materials. It can be
colored or colorless, monochrome or polychrome, transparent, translucent, or opaque. It is
lightweight impermeable to liquids, readily cleaned and reused, durable yet fragile, and often
very beautiful Glass can be decorated in multiple ways and its optical properties are
5
5
exceptional. In all its myriad forms - as table ware, containers, in architecture and design - glass
represents a major achievement in the history of technological developments.
5
Since the Bronze Age about 3,000 B.C., glass lias been used for making various kinds
of objects. It was first made from a mixture of silica, line and an alkali such as soda or potash,
and these remained the basic ingredients of glass until the development of lead glass in the
10 seventeenth century. When heated, the mixture becomes soft and malleable and can be formed
5
by various techniques into a vast array of shapes and sizes. The homogeneous mass thus formed
5
by melting then cools to create glass, but in contrast to most materials formed in this way
(metals, for instance), glass lacks the crystalline structure normally associated with solids, and
instead retains the random molecular structure of a liquid. In effect, as molten glass cools, it
15 progressively stiffens until rigid, but does so without setting up a network of interlocking
5
crystals customarily associated with that process. This is why glass shatters so easily whendealt
5
a blow. Why glass deteriorates over time, especially when exposed to moisture, and why
glassware must be slowly reheated and uniformly cooled after manufacture to release internal
stresses induced by uneven cooling.
Another unusual feature of glass is the manner in which its viscosity changes as it
20
5
5
turns from a cold substance into a hot, ductile liquid. Unlike metals that flow or"freeze" at
specific temperatures glass progressively softens as the temperature rises, going through
varying stages of malleability until it flows like a thick syrup. Each stage of malleability allows
the glass to be manipulated into various forms, by different techniques, and if suddenly cooled
25
5
the object retains the shape achieved at that point. Glass is thus amenable to a greater number
of heat-forming techniques than most other materials.
5
1.
Why does the author list the characteristics of glass in lines 1-6?
(A) To demonstrate how glass evolved
(B) To show the versatility of glass
(C) To explain glassmaking technology
(D) To explain the purpose of each component of glass
2.
The word "durable"' in line 3 is closest in meaning to
(A) lasting
(B) delicate
(C) heavy
(D) Plain
3.
What does the author imply about the raw materials used to make glass?
(A) They were the same for centuries.
(B) They are liquid
(C) They are transparent
(D) They are very heavy.
4.
According to the passage, how is glass that has cooled and become rigid different from
most other rigid substances?
(A) It has an interlocking crystal network.
(B) It has an unusually low melting temperature.
(C) It has varying physical properties.
(D) It has a random molecular structure.
5.
The word "customarily" in line 16 is closest in meaning to
(A) naturally
6.
(B) necessarily
(C) usually
(D) certainly
The words "exposed to" in line 17 are closest in meaning to
(A) hardened by
(B) chilled with
(C) subjected to
(D) deprived of
What must be done to release the internal stresses that build up in glass products during
manufacture?
7.
(A) the glass must be reheated and evenly cooled.
(B) the glass must be cooled quickly.
(C) The glass must be kept moist until cooled.
(D) The glass must be shaped to its desired form immediately
The word "induced" in line 19 is closest in meaning to
8.
(A) joined
(B) missed
(C) caused
(D) lost
(C) manner
(D) viscosity
The word "it" in line 20 refers to
9.
(A) feature
(B) glass
According to the passage, why can glass be more easily shaped into specific forms than
can metals
10.
(A) It resists breaking when heated
(B) It has better optical properties.
(C) It retains heat while its viscosity changes.
(D) It gradually becomes softer as its temperature rises.
Antibiotics & Immune System
The livelihood of each species in the vast and intricate assemblage of living things
depends on the existences of other organisms. This interdependence is sometimes subtle,
sometimes obvious. Perhaps the most straightforward dependence of one species
another
occurs with parasites, organisms that live on or in other living things and derive nutrients
5
directly from them. The parasitic way of life is widespread. A multitude of microorganisms
5
(including viruses and bacteria) and an army of invertebrates - or creatures lacking a spinal
5
column (including crustaceans, insects, and many different types of worms) -make their livings
directly at the expense of other creatures. In the face of this onslaught, living things have
evolved a variety of defense mechanisms for protecting their bodies from invasion by other
10 organisms.
5
Certain fungi and even some kinds of bacteria secrete substances known as antibiotics
5
into their external environment. These substances are capable of killing or inhibiting the growth
of various kinds of bacteria that also occupy the area, thereby eliminating or reducing the
competition for nutrients. The same principle is used in defense against invaders in other groups
15 of organisms. For example, when attacked by disease-causing fungi or bacteria, many kinds of
5
plants produce chemicals that help to ward off the invaders.
5
Members of the animal kingdom have developed a variety of defense mechanisms for
dealing with parasites. Although these mechanisms vary considerably, all major groups of
20 animals are capable of detecting and reacting to the presence of "foreign" cells. In fact,
5
throughout the animal kingdom, from sponges to certain types of worms, shellfish, and all
5
vertebrates (creatures possessing a spinal column), there is evidence that transplants of cells or
fragments of tissues into an animal are accepted only if they come from genetically compatible
or closely related individuals.
The ability to distinguish between "self" and "nonself", while present in all animals,
25
5
is most efficient among vertebrates, which have developed an immune system as their defense
5
mechanism. The immune system recognizes and takes action against foreign invaders and
transplanted tissues that are treated as foreign cells.
1.
What does the passage mainly discuss?
(A) how parasites reproduce
(B) how organisms react to invaders
(C) how antibiotics work to cure disease
(D) how the immune systems of vertebrates developed
2.
The word "intricate" in line 1 is closest in meaning to
(A) difficult
3.
(C) critical
(D) complex
The expression "an army" in line 6 is closest in meaning to
(A) an illness
4.
(B) widespread
(B) an attack (C) a large number
(D) a distinct type
According to the passage, some organisms produce antibiotics in order to
(A) prevent disease in humans (B) aid digestion
(C) fight off other organisms
5.
The word "vary" in line 19 is closest in meaning to
(A) differ (B) endure
6.
(D) create new types of nutrients
(C) balance
The word "they" in line 23 refers to
(A) sponges, worms and shellfish
(B) vertebrates
(C) individuals
(D) transplants
(D) contribute
7.
According to the passage, a transplant of tissue between genetically incompatible organisms
will result in the transplanted tissue
(A) becoming a parasite
(B) being treated as an invader
(C) altering its genetic makeup
(D) developing a new immune system
8.
According to the passage, the ability to distinguish between "self" and "nonself" enables
vertebrates to
(A) accept transplanted cells
(B) detect and react to invasion
(C) weaken their immune system
(D) get rid of antibiotics
9.
All of the following ate defined in the passage EXCEPT
(A) parasites(line 4)
(B) invertebrates(line7)
(C) nutrients (line14)
(D) vertebrates(line 22)
10.
The paragraph following the passage most probably discusses
(A) how the immune system in vertebrates fights off foreign cells
(B) different types of bacteria and lung
(C) how vertebrates and invertebrates differ
(D) examples of different groups of organisms
Semut ( ant )
Many ants forage across the countryside in large numbers and undertake mass
migrations; these activities proceed because one ant lays a trail on the ground for the others to
follow. As a worker ant returns home after finding a source of food, it marks the route by
intermittently touching its stinger to the ground and depositing a tiny amount of trail
5 pheromone—a mixture of chemicals that delivers diverse messages as the context changes.
These trails incorporate no directional information and may be followed by other ants in either
5
5
direction.
Unlike some other messages, such as the one arising from a dead ant, a food trail has
to be kept secret from members of other species. It is not surprising then that ant species use a
10 wide variety of compounds as trail pheromones. Ants can be extremely sensitive to these
5
signals. Investigators working with the trail pheromone of the leafcutter ant Atta texana
5
calculated that one milligram of this substance would suffice to lead a column of ants three
times around Earth.
The vapor of the evaporating pheromone over the trail guides an ant along the way,
15 and the ant detects this signal with receptors in its antennae. A trail pheromone will evaporate
to furnish the highest concentration of vapor right over the trail, in what is called a vapor space.
5
5
In following the trail, the ant moves to the right and left, oscillating from side to side across the
line of the trail itself, bringing first one and then the other antenna into the vapor space. As the
ant moves to the right, its left antenna arrives in the vapor space. The signal it receives causes
20 it to swing to the left, and the ant then pursues this new course until its right antenna reaches
5
the vapor space. It then swings back to the right, and so weaves back and forth down the trail.
5
1.
What does the passage mainly discuss?
(A) The mass migration of ants
(B) How ants mark and follow a chemical trail
(C) Different species of ants around the world
(D) The information contained in pheromones
2.
The word “forage” in line 1 is closest in meaning to
(A) look up
(B) walk toward
(C) revolve around
(D) search for food
3.
The word “intermittently” in live 4 is closest in meaning to
(A) periodically
(B) incorrectly
(C) rapidly
(D) roughly
4.
The phrase “the one” in line 8 refers to a single
(A) message
(B) dead ant
(C) food trail
(D) species
5.
According to the passage, why do ants use different compounds as trail pheromones?
(A) To reduce their sensitivity to some chemicals
(B) To attract different types of ants
(C) To protect their trail from other species
(D) To indicate how far away the food is
6.
The author mentions the trail pheromone of the leafcutter ant in line 10 to point out
(A) how little pheromone is needed to mark a trail
(B) the different types of pheromones ants can produce
(C) a type of ant that is common in many parts of the world
(D) that certain ants can produce up to one milligram of pheromone
7.
According to the passage, how are ants guided by trail pheromones?
(A) They concentrate on the smell of food.
(B) They follow an ant who is familiar with the trail
(C) They avoid the vapor spaces by moving in a straight line.
(D) They sense the vapor through their antennae.
8.
The word “furnish” in line 16 is closest in meaning to
(A) include
(B) provide
(C) cover
(D) select
9.
The word “oscillating “ in line 17 is closest in meaning to
(A) falling
(B) depositing
(C) swinging
(D) starting
10.
According to the passage, the highest amount of pheromone vapor is found
(A) in the receptors of the ants
(B) just above the trail
(C) in the source of food
(D) under the soil along the trail
Death Valley
In Death Valley, California, one of the hottest, most arid places in North America, there
is much salt, and salt can damage rocks impressively. Inhabitants of areas elsewhere, where
streets and highways are salted to control ice, are familiar with the resulting rust and
deterioration on cars. That attests to the chemically corrosive nature of salt, but it is not the
5
way salt destroys rocks. Salt breaks rocks apart principally by a process called crystal prying
5
and wedging. This happens not by soaking the rocks in salt water, but by moistening their
5
bottoms with salt water. Such conditions exist in many areas along the eastern edge of central
Death Valley. There, salty water rises from the groundwater table by capillary action through
tiny spaces in sediment until it reaches the surface.
Most stones have capillary passages that suck salt water from the wet ground. Death
10
5
5
Valley provides an ultra-dry atmosphere and high daily temperatures, which promote
evaporation and the formation of salt crystals along the cracks or other openings within stones.
These crystals grow as long as salt water is available. Like tree roots breaking up a sidewalk,
the growing crystals exert pressure on the rock and eventually pry the rock apart along planes
15 of weakness, such as banding in metamorphic rocks, bedding in sedimentary rocks, or
5
5
preexisting or incipient fractions, and along boundaries between individual mineral crystals or
grains. Besides crystal growth, the expansion of halite crystals (the same as everyday table salt)
by heating and of sulfates and similar salts by hydration can contribute additional stresses. A
rock durable enough to have withstood natural conditions for a very long time in other areas
20 could probably be shattered into small pieces by salt weathering within a few generations.
5
The dominant salt in Death Valley is halite, or sodium chloride, but other salts, mostly
5
carbonates and sulfates, also cause prying and wedging, as does ordinary ice. Weathering by a
variety of salts, though often subtle, is a worldwide phenomenon. Not restricted to arid regions,
25 intense salt weathering occurs mostly in salt-rich places like the seashore, near the large saline
5
lakes in the Dry Valleys of Antarctica, and in desert sections of Australia, New Zealand, and
5
central Asia.
1.
What is the passage mainly about?
(A) The destructive effects of salt on rocks.
(B) The impressive salt rocks in Death Valley.
(C) The amount of salt produced in Death Valley.
(D) The damaging effects of salt on roads and highways.
2.
The word "it" in line 9 refers to
(A) salty water
3.
(B) groundwater table
(C) capillary action
(D) sediment
The word "exert" in line 14 is closest in meaning to
(A) put
(B) reduce
(C) replace
(D) control
4.
In lines 13-17, why does the author compare tree roots with growing salt crystals?
(A) They both force hard surfaces to crack.
(B) They both grow as long as water is available.
(C) They both react quickly to a rise in temperature.
(D) They both cause salty water to rise from the groundwater table.
5.
In lines 17-19, the author mentions the "expansion of halite crystals...by heating and of
sulfates and similar salts by hydration" in order to
(A) present an alternative theory about crystal growth
(B) explain how some rocks are not affected by salt
(C) simplify the explanation of crystal prying and wedging
(D) introduce additional means by which crystals destroy rocks
6.
The word "durable" in line 19 is closest in meaning to
(A) large (B) strong
7.
8.
9.
(C) flexible
(D) pressured
The word "shattered" in line 20 is closest in meaning to
(A) arranged
(B) dissolved
(C) broken apart
(D) gathered together
The word "dominant" in line 22 is closest in meaning to
(A) most recent
(B) most common
(C) least available
(D) least damaging
According to the passage, which of the following is true about the effects of salts on rocks?
(A) Only two types of salts cause prying and wedging.
(B) Salts usually cause damage only in combination with ice.
(C) A variety of salts in all kinds of environments can cause weathering.
(D) Salt damage at the seashore is more severe than salt damage in Death Valley.
Which of the following can be inferred from the passage about rocks that are found in
areas where ice is common?
10.
(A) They are protected from weathering.
(B) They do not allow capillary action of water.
(C) They show similar kinds of damage as rocks in Death Valley.
(D) They contain more carbonates than sulfates.