04-2284-0322 ex 743
Room 743, Instruction Building

Theme-Based English 1
Lesson One
On the Web, College Classes With No Charge (or Credit)
Knowledge is free on the Internet at a small but growing number of colleges and universities. About one hundred sixty schools around the world now offer course materials free online to the public. Recent additions in the United States projects at
Yale, Johns Hopkins and the University of California, Berkeley.
Berkeley said it will offer videos of lectures on YouTube. Free videos from other schools are at the Apple iTunes store.
The Massachusetts Institute of Technology became an early leader with its
OpenCourseWare project, first announced in 2001. Free lecture notes, exams and other resources are at ocw.mit.edu. Many exams and homework assignments even include the answers. The Web site also has videos of lectures and .
Today, OpenCourseWare offers materials from one thousand eight hundred undergraduate and graduate courses. These range from physics and linear algebra to anthropology, political -- even scuba diving.
Visitors can learn the same things M.I.T. students learn. But as the site points out,
OpenCourseWare is not an M.I.T. education. Visitors receive no credit toward a . Some materials from a course may not be available, and the site does not provide contact with teachers.
Still, M.I.T. says the site has had forty million visits by thirty-one million visitors from almost every country. Sixty percent of the are from outside the United
States and Canada.
There are links to materials translated into Spanish, Portuguese, Chinese and Thai.
OpenCourseWare averages one million visits each month, and the receive half a million more. Students and educators use the site, including students at M.I.T. But the largest number of visitors, about half, are self-learners.
Some professors have become well known around the world as a result of appearing online. Walter Lewin, a physics professor at M.I.T., is especially . Fans enjoy his entertaining demonstrations. M.I.T. OpenCourseWare now includes materials for high school. The goal is to improve in science, technology, math and engineering.
Questions for Discussion
1.
What is the main idea of the lesson?
2.
What is your reflection on the lesson?

Theme-Based English 2
Lesson Two
Children, Self-Control and 'Executive Function'
Executive function. What do you suppose that is? Mental health professionals, educators and others use this term when talking about ways that people exercise self-control. Executive function involves the skills we need to our lives.
Experts at the National Center for Learning Disabilities say we use executive function to study situations, plan, act and change our minds. They say problems with executive function are strongly linked to deficits and learning disabilities.
All of these problems can have some of the same signs -- for example, trouble with working .
What is working memory? This term is commonly used now in place of short-term memory. It describes the brain's ability to store recent information , but also to use and make sense of it.
Researchers say good executive function is important for success in school.
Students with poor executive function need help to organize research. They have serious deciding which of two or three tasks to do first. They have difficulty changing tasks or working on one project for a long period of time.
A person might have trouble waiting and cooperating, and might say or do things even if it others.
Laura Berk in the psychology department at Illinois State University is an expert on the subject. She says executive function skills can be improved.
For example, Professor Berk says games of Simon Says can help young children learn to exercise self-control by NOT doing something. Children are given but told to follow them only when the leader begins a direction by saying "Simon says ... "
She also suggests a game called Freeze. Children dance to music until the music stops. Then they have to place their bodies in a shown in a picture.
She says giving children a chance to use their imaginations for make-believe play can also help them executive function skills.
Teenagers and adults can write lists and establish ways to make sure they do important tasks. Technology can help. For example, online banking services can be set up to pay bills . And alarm clocks on cell phones can remind someone when it is time to go to work or be in class.
Questions for Discussion
1.
What is the main idea of the lesson?
2.
What is your reflection on the lesson?

Theme-Based English 3
Lesson Three
In Some Schools, Learning Is Not Enough of Its Own Reward
Some American schools pay teachers more if their students improve on tests. Now, there is a growing movement to pay the students -- in some cases, even just for coming to class.
Students at one school in New Mexico can earn up to three hundred dollars a year for good . A program in New York City pays up to five hundred dollars for good attendance and high test scores.
In Baltimore, Maryland, high scores on state graduation tests can be worth more than one hundred dollars. And a New Jersey school system plans to pay students fifty dollars a week to attend after-school tutoring .
Schools that pay students can be found in more than one-fourth of the fifty states.
Other schools pay students with food or other rewards. Robert Schaefer is education director for the National Center for Fair and Open Testing, an activist group. He says paying may improve performance in the short term, but students develop false expectations for the future. He sees a lack of long-term planning in these programs because of on schools to raise test scores.
Public schools need to show improvement under the education reform law signed by
President Bush six years ago. Low-performing schools may lose their federal money; teachers and may lose their jobs. Often these schools are in poor neighborhoods where getting students to go to school can be a continual problem.
Critics say paying students sends a that money is the only valuable reward. But some students say it makes school more exciting. And some teachers have reported getting more requests for extra help.
In 2004, the city schools in Coshocton, Ohio, a program. They wanted to see if paying elementary school students as much as one hundred dollars would help in passing state .
Now, Eric Bettinger of Case Western Reserve University has reported mixed results.
Math scores increased, but only while students were able to get paid. And there was no of higher scores in reading, social studies and science. Officials will decide later this year whether to continue the program.
Yet adults get paid for their work. And if teachers can be for their students' work, then why not the students themselves? This is what some people say. What do you think?
Questions for Discussion
1.
What is the main idea of the lesson?
2.
What is your reflection on the lesson?

Theme-Based English 4
Lesson Four
Too Many Americans Do Not Finish High School
A new report says only about half of all students in the main school systems of
America's largest cities finish high school. The report notes higher rates of graduation -- more than seventy percent -- in areas surrounding the cities. The Editorial Projects in
Education Research Center prepared the report.
Researchers studied high school rates from the 2003, 2004 school year.
They also identified the nation's fifty largest cities. The largest, New York City, had a of more than eight million. The smallest city was Wichita, Kansas. It had about three hundred sixty thousand people.
Researchers used a system of measurement called the promotion index to find graduation rates. School officials in many of the cities studied say the resulting were too low. That is because different areas use different methods to find graduation rates.
Critics say many methods do not give a true picture of the number of students who leave high school before .
Other studies have put the national graduation rate at about seventy percent. But experts agree that too many students are not completing high school. They the number at more than one million each year.
The report was prepared for America’s Promise Alliance. The private group aims to help children receive they need to succeed.
General Colin Powell was chairman of America's Promise Alliance when it was formed in 1997. He attended the press conference Tuesday where the report was . He said studies have shown that the United States must do more to educate the leaders and work force of the future.
Secretary of Education Margaret Spellings also spoke. She said the government will propose that states use the same methods when reporting graduation rates.
Alliance officials also announced the start of a nationwide campaign to improve graduation rates. It is to include a series of to be held in every state over the next two years. The meetings will bring together elected leaders, business owners, students, parents and education . They will develop plans to increase the number of
Americans who finish high school.
Questions for Discussion
1.
What is the main idea of the lesson?
2.
What is your reflection on the lesson?

Theme-Based English 5
Lesson Five
Questioning a Popular Approach to Lasting Development
If you give something to someone for free, will that person value it and use it?
Development experts have debated this question for decades. Some say the act of paying causes people to value something and use it more. Others argue that selling necessary health may deny them to the people who need them the most.
Consider, for example, chemically treated bed nets. These bed nets kill mosquitoes and protect people against malaria while they are sleeping. New York University
William Easterly says this is one example of development gone wrong. In a recent book,
Professor Easterly suggests bed nets given freely in Africa are often used for the wrong .
Yet, the World Health Organization recommends bed nets be given out freely and used by whole communities. The success of a large free bed net campaign in Kenya led the
W.H.O. to this recommendation last August.
This debate will likely influence social programs in the developing world. Many non-governmental organizations support the creation of self-sustaining in poor countries. Goods and services are sold for a price to help these programs survive.
Rachel Glennerster runs the Abdul Latif Jameel Poverty Action Lab at the
Massachusetts Institute of Technology. The research lab does and poverty studies. Its goal is to improve the effectiveness of anti-poverty programs in the United
States and other countries.
Miz Glennerster tells us that several by the research group's economists have proven that small price changes have a big influence on the number of people who use a product. A price change will the total amount of use of the product as well, she says. The economists have also found no evidence that the very act of paying for something changes how people use it.
Finally, some development argue that pricing is useful when targeting a product among special populations. When it comes to bed nets, Miz Glennerster says research shows no of this. People are just as likely to use a bed net if they paid for it or not.
Questions for Discussion
1.
What is the main idea of the lesson?
2.
What is your reflection on the lesson?

Theme-Based English 6
Lesson Six
The Price of Pleasure
Usually we think about material qualities when we think about the pleasure we will get from a product. When something costs a lot, we might think about all the fine work that went into it. But can price alone the pleasure we experience?
Researchers from the California Institute of Technology and the Stanford Graduate
School of Business say yes.
Hilke Plassmann, John O'Doherty and Antonio Rangel at Caltech and Baba Shiv at
Stanford did a study. They had twenty people taste different wines. Wine was chosen because it comes in many different qualities and prices, and because a lot of people enjoy it.
The people were told they were tasting five different Cabernet Sauvignons. The wines were only by price: five, ten, thirty-five, forty-five and ninety dollars.
But in truth there were only three different wines, and two of them were twice, at a high price and a low price. For example, the wine that in fact cost ninety dollars a was presented half the time as a ten dollar wine.
There were two important results from the study.
First, the individuals, on , reported greater pleasure from drinking wine that they were told was higher in price. Brain images taken while the people tasted the wine this finding.
Activity, represented by blood-oxygen levels, increased in an area of the brain thought to process "experienced pleasantness." Experiments have shown that the medial orbitofrontal cortex the experience of enjoyment from smells, taste and music.
The new findings will add to the limited knowledge of how marketing brain activity.
The second result has meaning for economists and marketers. The experiment appears to that raising the price can increase how much a product is enjoyed.
In other words, when it comes to expectations, it seems you really do get what you pay for.
The study is in the Proceedings of the National Academy of Sciences.
Questions for Discussion
1.
What is the main idea of the lesson?
2.
What is your reflection on the lesson?

Theme-Based English 7
Lesson Seven
A Business Plan for Social Change
Starting a business is never easy. But an organization like TechnoServe can make it easier. A businessman in the American state of Connecticut, Ed Bullard, launched this group forty years ago. The name comes from the idea of technology in the service of mankind.
TechnoServe looks for business to rural poverty. Or, as it says on its
Web site, "social change has a business plan." The group has helped create or more than two thousand businesses in about thirty countries.
Luba Vangelova works for TechnoServe in Washington, D.C. She tells us the group has an estimated this year of about forty-five million dollars. She says much of that will support business training and development programs in Latin America, Africa,
Asia and Eastern Europe.
In parts of Central America, for example, TechnoServe is helping coffee producers become in new and growing markets. In rural India the group is assisting farmers with crop production. And in Mozambique, TechnoServe is helping develop the travel and tourism .
One way it identifies promising entrepreneurs is through a business plan competition called Believe Begin Become. This is an program that provides technical training and expert advice.
Winners receive money to bring their business plans to . TechnoServe has held nine national competitions in Central America since 2002 Five competitions have been held in Africa, including one in Tanzania last year.
SPEAKER: "B.B.B. has been a breakthrough for me. Finally I am going to own my own business. And I am going to employ people."
A TechnoServe on YouTube describes Believe Begin Become and some of the winning business plans. Luba Vangelova says TechnoServe also supports entrepreneurship programs for teenagers and young adults.
Charity Navigator, an independent group that rates American , has given TechnoServe its highest rating.
Questions for Discussion
1.
What is the main idea of the lesson?
2.
What is your reflection on the lesson?

Theme-Based English 8
Lesson Eight
Building a Better Cook Stove for the World’s Poor
Breathing smoke from cooking stoves or open fires is a common cause of lung infections in developing countries. Indoor air pollution is blamed for an estimated four thousand deaths every day, mostly women and children.
A nonprofit group based in the American state of Colorado is working to save lives.
Researchers at Envirofit International have developed a clean-burning cook stove that uses less fuel and smoke.
They say it cuts the smoke and dangerous gases by up to eighty percent compared to open fires or simple traditional stoves. The cook stove was designed to the greatest amount of heat in the shortest amount of time and with the least amount of fuel. It can burn wood, animal waste or crop .
The Shell Foundation has formed a partnership with Envirofit to market the cook stoves. The British charity, established by the Shell Group in the year 2000, has ten million dollars in a pilot project for India.
Martha Kohlhagen at Envirofit tells us that as many as ten million stoves will be sent to southern India by the end of this year. She says the stoves are being in
China and will begin arriving in May. The stoves are designed to have a lifetime of up to three years at a cost of about fifteen dollars.
After India, the plan is to them to China and Brazil, and to other countries around the world. Envirofit expects twenty-five million dollars from the Shell
Foundation and other donors over the next five years to its efforts.
Nongovernmental organizations and local stores, in some cases, will sell the stoves in villages. The price in different countries will be based on demand and local economic .
Martha Kohlhagen says Envirofit will also work with local micro lending organizations to help support the sale of the stoves.
Envirofit says it will use any future from the stoves for further research and development. The group wants to develop combination technology, to be able use energy from the cook stove to things like heat or light.
Two students at Colorado State University, Tim Bauer and Nathan Lorenz, started
Envirofit International in 2003. The group has ties to the university. Envirofit developed from research work in the Engines and Energy Conversion Laboratory at Colorado State.
Questions for Discussion
1.
What is the main idea of the lesson?
2.
What is your reflection on the lesson?

Theme-Based English 9
Lesson Nine
Skin Care: Don't Let a Little Cut Fool You
Even minor cuts can become infected if they are left untreated. Any break in the skin can let bacteria enter the body. An increasing number of bacterial skin infections are resistant to antibiotic . These infections can spread throughout the body.
But taking good care of any injury that breaks the skin can help prevent an infection.
Medical experts say the first step in a wound is to use clean water. Lake or ocean water should not be used. To clean the area around the wound, experts suggest using a clean cloth and soap. They say there is no need to use like hydrogen peroxide or iodine.
It is important to remove all dirt and other material from the wound. After the wound is clean, use a small amount of antibiotic ointment or cream. Studies have shown that these medicated products can aid in . They also help to keep the surface of the wound from becoming dry. Finally, cover the cut with a clean bandage while it heals.
Change the daily and keep the wound clean.
As the wound heals, inspect for signs of infection including increased pain, redness and fluid around the cut. A high body temperature is also a sign of infection. If a wound seems , let the victim rest. Physical activity can spread the infection. If there are signs of infection, seek help from a doctor or other skilled medical .
For larger wounds, or in case bleeding does not stop quickly, use direct pressure.
Place a clean piece of cloth on the area and hold it firmly in place until the bleeding stops or medical help .
Direct pressure should be kept on a wound for about twenty minutes. Do not remove the cloth if the blood drips through it. Instead, put another cloth on top and continue . Use more pressure if the bleeding has not stopped after twenty minutes. Deep cuts usually require immediate attention from trained medical providers.
Doctors suggest getting a tetanus every ten years. A tetanus booster shot may be required if a wound is deep or dirty.
To learn more about first aid, contact a hospital or local organization like a Red
Cross or Red Crescent society. There may be training programs offered in your area.
Questions for Discussion
1.
What is the main idea of the lesson?
2.
What is your reflection on the lesson?

Theme-Based English 10
Lesson Ten
WHO Sees Tobacco Risk to a Billion Lives This Century
The World Health Organization is urging countries to follow six policies to prevent millions of tobacco-related deaths. The six policies are known as MPOWER, spelled
M-P-O-W-E-R.
The M is for monitoring tobacco use and policies. The P is for protecting people by establishing smoke-free areas.
O stands for offering services to help people stop smoking. W is for warning people about the dangers of tobacco.
E is for enforcing bans on tobacco advertising and other forms of marketing. And R is for taxes on tobacco.
The W.H.O. says in a major new report that raising taxes is the single most effective way to reduce tobacco use. A study found that governments now collect an average of five hundred times more money in tobacco taxes each year than they spend on efforts.
The W.H.O. says tobacco now causes more than five million deaths a year. It predicts this number will rise to more than eight million by the year 2030. By the end of the century, it says, tobacco could kill one people -- ten times as many as in the twentieth century.
The large majority of these deaths will take place in developing countries. More than twenty-five percent of all in the world are Chinese. India, Indonesia, Russia and the United States, in that order, follow China in tobacco use.
The W.H.O. found that only five percent of all people live in countries with like national legislation on smoke-free areas or bans on tobacco advertising. Forty percent of countries still permit smoking in hospitals and schools.
An international treaty on tobacco control came into in 2005. Tobacco companies face increasingly restrictive marketplaces in many wealthier countries. The industry is now aiming at the developing world, especially young women. The report says large numbers of people do not yet know the of smoking.
W.H.O. Director General Margaret Chan points out that tobacco hurts economies in two ways. One is through reduced among workers who get lung cancer or other tobacco-related diseases. The other way is through high health care costs for treating those .
The W.H.O. study was announced in New York City. New York's mayor, Michael
Bloomberg, has worked hard to restrict smoking in America's largest city. And his charitable group, Bloomberg Philanthropies, helped pay for the study.
Questions for Discussion
1.
What is the main idea of the lesson?
2.
What is your reflection on the lesson?

Theme-Based English 11
Lesson Eleven
The Dark Side of Skin Lightening
In many societies, there is often greater acceptance of light skin than dark skin.
Light skin may be seen as a mark of beauty, intelligence and success. These beliefs can lead to social pressures even within the same racial or ethnic group, if some members are skinned than others.
The result is that skin lightening has become a common activity across Africa, Asia and other areas of the world. More and more people with dark skin are using skin-lightening products, even if it means they may face health .
They believe that having whiter skin will improve their lives. Many people think they will have a better chance of getting a job or marrying into a better family. Or they want to look like what their generally considers beautiful.
Some beauty care products and soaps contain chemicals that make skin lighter. This process is also called bleaching. But some of the chemicals are extremely . One of the most dangerous is hydroquinone.
Hydroquinone has been banned in several countries. This has been linked to kidney damage and some kinds of cancer. It also causes low birth weight in babies when mothers use it during .
At first, bleaching products make the skin color lighter. But after long-term use they can cause problems. They could even make some skin darker.
The chemicals in the products and break down the natural process that gives color to skin. The skin loses its natural barrier to protect against sunlight. Then the skin can become thick and discolored. Usually the person will use more of the product in an effort to correct the problem, but this only makes it .
Fatimata Ly treats skin conditions in the Senegalese capital, Dakar. Doctor Ly says skin bleaching has become a problem throughout Senegal. She says the chemicals are now more dangerous because they are . Some cases have resulted in blackened fingernails, infections and permanent skin damage.
And these are not the only risks. Experts say some people who change their skin color suffer damage. They feel regret and sadness. They feel that instead of risking their health, they should have learned to love and accept their skin color as it was.
Questions for Discussion
1.
What is the main idea of the lesson?
2.
What is your reflection on the lesson?

Theme-Based English 12
Lesson Twelve
How to Do Hands-Only CPR
Cardiopulmonary resuscitation, or CPR, is help for a stopped heart. It increases the chances of survival and reduces the danger of brain damage. With traditional CPR, you push hard on the chest thirty times, then stop to give two breaths to force air into the lungs.
You the steps until the victim can get medical treatment.
But people may worry about getting sick from blowing into a stranger's mouth. Also, the training is easy to forget, especially in a crisis. And those without training may be afraid to do anything for fear they will do something .
So now, the American Heart Association has simplified its guidelines and is calling for hands-only CPR. Here is how it works:
A person has collapsed and is . The victim has lost color in the face and does not appear to be breathing. These are signs of cardiac arrest -- and this is the time to begin CPR.
Place your hands, one on top of the other, on the of the chest. Push hard and fast. Aim for a rate of about one hundred presses in a minute. Chest compressions keep the blood flowing to the brain, heart and other .
CPR guidelines from 2005 said only untrained people should use this method.
Those with training were told to use traditional CPR. But now the American Heart
Association says everyone should use hands-only CPR unless they feel strong about their ability to do breathing.
The organization says the hands-only method was just as effective as traditional
CPR in several studies. Scientists say there is enough oxygen in a person’s system for several minutes after breathing stops. They also say people need less oxygen when the heart is at rest.
The American Heart Association recommends hands-only CPR for use on adults who suddenly collapse. It says traditional CPR with a of breaths and compressions should be used for babies and children. Traditional CPR should also be used for adults who are found already unconscious and not breathing normally. And it should be used for any victims of drowning or from breathing problems.
These are all examples of cases where CPR with mouth-to-mouth breathing may be more helpful that hands-only CPR. The American Heart Association says because there are many such cases, people should still learn CPR that mouth-to-mouth.
Questions for Discussion
1.
What is the main idea of the lesson?
2.
What is your reflection on the lesson?

Theme-Based English 13
Lesson Thirteen
Giving Grasslands a Rest
Grasslands need time to rest when cattle and other animals feed on them. Moving animals from one area of pasture to another can provide the time needed for new growth.
This is called grazing, and we have a question from listener Zhang Guohui in
China about how it works.
Experts say rotational grazing is good for the land and the animals, and it can save money. This form of grazing can reduce the need for chemicals by reducing the growth of weeds. And it can limit the need for chemical fertilizers by letting natural fertilizer, animal droppings, do the job. Rotational grazing can even help wildfires by keeping grasslands in good condition.
Letting animals feed continually and intensively in the same grazing areas can require costly replanting. Animals eat the most growth first. When that keeps happening, the roots do not have enough time to recover. As a result, less desirable plants may them.
Intensively used grasslands are also harmed as the soil is continually crushed under the weight of heavy animals. And the animals usually avoid their own waste, so that the amount of good grazing space even more.
Experts say that while rotational grazing can save money over time, it also requires planning. And that starts with a good map to mark fences, water and grazing areas.
Changing methods of grazing also requires time. Farmers may want to put up electric fences to enclose grazing areas, called paddocks. The paddocks will need water.
Some farmers a path for animals from different paddocks to drink from a common watering place.
Farmers can start rotational grazing by removing animals from a pasture when the grass is eaten to less than five . The pasture is then kept empty until the grass grows to more than fifteen centimeters high.
Experts say sheep and goats may require special . They may need stronger fences than other animals. And while they eat the grass, they may need guard animals like llamas to protect them from animals that would like to eat them.
Questions for Discussion
1.
What is the main idea of the lesson?
2.
What is your reflection on the lesson?

Theme-Based English 14
Lesson Fourteen
The Danger of Desertification
Desertification is a process. It changes productive land into useless land. One example of desertification is when a desert spreads into nearby cropland. In time, the cropland becomes an of the desert.
But that is not the only way farmers lose fertile soil.
Long dry periods, warmer temperatures and the removal of trees can all lead to the loss of good cropland. Floods can remove fertile topsoil and begin a resulting in the loss of planting areas.
Another danger to good land is poor farming methods. Farmers should avoid continually planting crops in the same places, or letting animals year after year on the same lands.
Countries from Guatemala to Greece to Vietnam are working against the loss of cropland. Africa especially faces the risk of desertification.
Nigeria, for example, says it loses three hundred fifty thousand hectares of usable land each year. Hills of now cover places where people once lived.
When cropland turns to desert, people move to other places for better land and better jobs. This can cause political and social tensions.
A nonprofit organization in Nigeria is working to bring public attention to the problem. The group is called Fighting Against Desert Encroachment, or FADE.
Newton Jibunoh is a retired soil who started this group in the year 2000.
He says desert encroachment could cause widespread hunger.
Newton Jibunoh is currently leading a delegation to thirteen African countries to the dangers of losing farmlands. In northern Nigeria, the group organized a competition between schools in seven areas. The goal was to see who could plant the most trees.
Trees are often cut down for wood. But lines of trees around cropland can catch blowing sand. In addition, tree roots can hold soil in place. Even within a desert, trees can be planted as borders around grassy areas.
For many years, China has been a wall of trees in the northern part of the country. The goal is to stop the Gobi Desert from extending toward Beijing. The Great
Green Wall will extend about five thousand kilometers. Completion is in 2050.
Questions for Discussion
1.
What is the main idea of the lesson?
2.
What is your reflection on the lesson?

Theme-Based English 15
Lesson Fifteen
The Seeds of Weed Control
When is a plant a weed? When its undesirable qualities outweigh its good points, say experts at Penn State University.
Weeds can take control of productive land. Crops generally produce several hundred seeds per plant. But each weed plant can produce tens or even hundreds of thousands of seeds. And some buried seeds can up to forty years, or even longer.
Eradicating weeds means you have to remove all the seeds and roots so the plants will not grow back. But birds or the wind can reintroduce them to the land.
A more common way to deal with weeds is to control them enough so that the land can be used for planting. Experts using two or more control methods.
Chemical weed killers or natural treatments like corn gluten can suppress weed growth. Dense planting of a crop can also act as a natural control. Bill Curran is a professor of weed science at Penn State, in University Park, Pennsylvania. He says planting is one of the most common methods for suppressing weeds.
He says a dense, competitive crop that quickly shades the soil will help suppress many weeds. The seeds need light to grow, so blocking the sun will weed growth.
Other controls include turning over the soil, pulling the weeds by hand or covering them with mulch made from wood, garden waste or other material. Mulch is used, but even mulch has its limits. Natural resource specialists in the Queensland government in Australia note that weeds can be transported in mulch. This is also true of soil, grain, hay and .
Yet animals like sheep or goats can provide a biological control by eating weeds.
Insects and other organisms can also act as controls.
Preventing the spread of weeds is an important part of weed management. Farm vehicles should be kept out of areas with weeds. If that is not possible, then clean off the
and your shoes when leaving.
People in Queensland are advised to take weeds and garden waste to a waste center or burn them, bury them deeply or them into mulch.
Professor Curran says composting weeds is another way to make use of them. The process of making organically rich compost produces heat. This will kill many, though not all, weed seeds. The same is true of seeds that pass through farm animals that on weeds.
Questions for Discussion
1.
What is the main idea of the lesson?
2.
What is your reflection on the lesson?

Theme-Based English 16
Lesson Sixteen
Honey Bee Losses Still a Problem in US
Honey bees add billions of dollars in value to around one hundred thirty crops in the United States. But since the 1980’s researchers have been concerned about the health of these valuable pollinators.
Worries grew after the winter of 2006. Some pollination reported losses of anywhere from thirty to ninety percent of their hives. The beekeepers did not find dead adult bees as they often do after winter. Instead, the bees were gone. Experts gave a name to this mysterious situation: colony collapse .
A report in Agricultural Research magazine, from the Department of Agriculture, takes a fresh look at C.C.D. It says the disorder is truly a serious problem. But it says there were enough honey bees to provide all the pollination needed last year.
Still, beekeepers reported losing about thirty-five percent of their hives in the fall and winter of 2007. In 2006, it was thirty-one percent.
The United States has almost two and one-half million beehives.
Experts from the Agriculture Department and the Apiary Inspectors of America did a study involving about one-fifth of them.
One finding was that beekeepers who found no dead adult bees were more likely to have the most losses. Also, a virus called I.A.P.V., for Israeli acute paralysis virus, was present in almost half the colonies studied.
But researchers say they do not know if this virus causes a colony to .
They say the lack of affected bees to examine makes it difficult to know exactly what the new disorder is.
Losses in honey bee populations can result from a number of . A big problem, for example, is the varroa mite, a deadly parasite. And experts keep looking for other answers for the current situation.
Scientists at the University of Virginia recently reported that air may prevent bees from finding flowers to pollinate. They think ozone in the air is keeping bees and other pollinators from smelling the flowers. Bees feed on nectar and pollen from .
Jose Fuentes and his team at Virginia studied how far the scent of flowers travels with the wind. Before the 1800’s, they say, it was more than one thousand two hundred meters. Now, they say, the scent can only about three hundred meters at best.
Their study is in the journal Atmospheric Environment.
Questions for Discussion
1.
What is the main idea of the lesson?
2.
What is your reflection on the lesson?