1 . Eating too much fatty food, exercising too little and smoking can raise your future risk of heart disease. But there is another factor that can cause your heart problems more immediately: the air you breathe.

Previous studies have linked high exposure (暴露) to environmental pollution to an increased risk of heart problems, but two analyses now show that poor air quality can lead to heart attack or stroke (中风) within as little as a few hours after exposure. In one review of :he research, scientists found that people exposed to high levels of pollutants (污染物) were up to 5% more likely to suffer a heart attack within days of exposure than those with lower exposure. A separate study of stroke patients showed that even air that the U. S. Environmental Protection Agency(EPA) considers to be of “moderate” (良好) quality and relatively safe for our health can raise the risk of stroke as much as 34% within 12 to 14 hours of exposure.

The authors of both studies stress that these risks are relatively (相对地) small for healthy people and certainly modest compared with other risk factors such as smoking and high blood pressure However, it is important to be aware of these dangers because everyone is exposed to air pollution regardless of lifestyle choices. So stricter regulations by the EPA of pollutants may not only improve environmental air quality but could also become necessary to protect public health.

1. The text mainly discusses the relationship between ________.

A．heart problems and exercising

B．heart problems and smoking

C．heart problems and fatty food

D．heart problems and air quality

2. What does the underlined word “modest” in Paragraph 3 most probably mean?

A．Relatively high.

B．Relatively low.

C．Too low.

D．Too high.

3. What can we learn from the text?

A．Stricter regulations on pollutants should be made.

B．Eating fatty food has immediate effects on your heart.

C．The EPA did many studies on air quality.

D．Moderate air quality is more harmful than smoking.

4. The author’s purpose of writing the text is most likely to ________.

A．introduce

B．describe

C．entertain

D．persuade

5 . Researchers have found a chemical from a kind of worm (蠕虫) can break down one of the most common forms of plastic. The finding could open up new ways to deal with pollution.

There have been several studies showing that microorganisms can release enzymes (酶) that cause the plastics to start to break down, but that process may take a long time. The recently-discovered enzymes were found in the saliva (唾液) of the waxworm. They appear to act in only a few hours.

Federica Bertocchini is one of the researchers, who is also a beekeeper and always stores honeycombs, which are built by bees to store honey. One year Bertocchini found her honeycombs full of waxworms. She cleaned the honeycombs and put the worms in a plastic bag. When she returned later, she found that the bag was full of holes. She wondered if the worms were eating the plastic, or if there was a chemical reaction that caused the holes. “We checked and found that the plastics had been broken down,” she said.

In her latest research, Bertocchini and her co-workers found two enzymes in the worm’s saliva. The enzymes appeared to break down plastics in only a few hours.

Bertocchini’s team is still trying to understand how the worms break down the plastics. They know much more research is needed before the findings can be used to process plastic waste. However, Bertocchini said the enzymes could be put into a water mixture and then put “over piles of collected plastics” in a waste center. She said that, in the future, the enzymes could be used in homes, where families could deal with their own plastic waste.

1. What can we learn about the microorganisms in para. 2?

A．They are fond of eating small pieces of plastics.

B．They are widely used to deal with plastic pollution.

C．It takes long for their enzymes to break down plastics.

D．They can easily produce a large amount of useful saliva in a short time.

2. How did Bertocchini make the discovery?

A．By accident.	B．By keeping waxworms.
C．By doing experiments.	D．By studying bees.

3. Why were there many holes in Bertocchini’s bag?

A．The bees flew to and bit it.	B．There was a chemical reaction.
C．There were some sharp things in it.	D．The worms chewed and swallowed the plastic.

4. What does the author think about the new method of breaking down plastics?

A．It’s a theoretical possibility, but it won’t happen.	B．It may replace the usual ways soon.
C．It is getting increasingly popular.	D．There is still a long way to go.

6 . Now, Earth Day is celebrated every year on April 22. A man, called Senator Gaylord Nelson Take, was determined to change the way we treated our planet. He didn’t stop his work until he had made a difference.

In 1963, Senator Gaylord Nelson wasn’t happy with the earth’s condition. He wanted to clean up the planet and solve pollution and environmental problems. As a senator, Gaylord Nelson was someone chosen by US citizens to help make laws, so he had a lot of power. He went to John F. Kennedy, the President at the time, with his concerns. The President agreed that the planet’s environment was a serious issue, so President Kennedy went around the country on a five­day tour to promote (宣传) the idea of cleaning up the planet. People began making small changes, but it wasn’t enough.

A few years later, Senator Nelson decided to put one day aside every year for the cause of saving the planet. On April 22,1970, the first Earth Day was celebrated; 20 million American demonstrators (示威者) took part in Earth Day activities. Since then, Earth Day has become an international holiday. People all over the world are doing something to make the earth a cleaner, better place. Today more than 500 million people in 164 countries participate (参与) in Earth Day festivities!

Then, what can you do to make a difference?

*Encourage your family to recycle on a regular basis. It is a good way to help the earth!

*Switch to energy­efficient light bulbs in your house to reduce the effects of global warming.

*Every glass bottle you recycle saves enough energy to run a TV for an hour and a half, while recycling an aluminum (铝) bottle can save enough energy to run your TV for three hours!

*Turn out the lights when you leave a room — unless someone’s still there!

*Use re­useable containers for your school lunches and snacks.

1. What does a senator usually do according to the passage?

A．Cleaning up the planet.	B．Solving population problems.
C．Helping make laws.	D．Talking to the President.

2. The first Earth Day was celebrated ________.

A．in America	B．in Britain
C．in 164 countries	D．across the world

3. How long can you use the energy to run a TV if you recycle an aluminum bottle?

A．For a half hour.	B．For an hour.
C．For an hour and a half.	D．For three hours.

4. Which of the following is TRUE according to the passage?

A．It was in 1963 that Senator Nelson came up with the idea of choosing a day as Earth Day.

B．John F. Kennedy agreed to put April 22 aside every year as Earth Day.

C．President Kennedy agreed with Nelson’s idea of cleaning up the planet.

D．More than 500 million people took part in the first Earth Day activities.

7 . In 1620, about half the USA was covered by forests.   Today the forests have almost gone.   A lot of good land has gone with them, leaving only sand.   China doesn’t want to copy the USA’s example.   We’re planting more and more trees.   We’ve built the “ Great Green Wall” of trees across northern part of our country. The Great Green Wall is 7,000 kilometres long, and between 400 and 1,700 kilometres wide.   It will stop the wind from blowing the earth away.   It will stop the sand from moving towards the rich farmland in the south.   More “Great Green Walls” are needed.   Trees must be grown all over the world.   Great Green Walls will make the world better.

1. In 1620, about ________ the USA was covered by forests.

A．a third

B．half

C．two thirds

D．a fourth

2. A lot of good land has gone with ________.

A．sand

B．water

C．wind

D．forests

3. The Great Green Wall in China is ________ long.

A．7,000 kilometers	B．1,700 kilometers
C．7,000 meters	D．400 kilometers

4. Trees must be grown in ________.

A．China	B．the USA
C．some countries	D．every part of the world

5. ________ will make the world better.

A．The Great Wall	B．Tall buildings
C．Great Green Walls	D．Flowers and grass

8 . 1970 was World Conservation Year. The United Nations wanted every one to know that the world is in danger. They hoped the governments would act quickly in order to “conserve” nature. Here is one example of the problem. At one time there were 1,300 different plants, trees and flowers in Holland, but now only 866 remain. The others have been destroyed by modern man and his technology. We are changing the earth, the air and water, and everything that grows and lives. We can’t live without these things. If we continue like this, we shall destroy ourselves.

What will happen in the future? Perhaps it is more important to ask “What must we do now?” The people who will be living in the world of tomorrow are the young of today. A lot of them know that con­servation is necessary. Many are helping to save our world. They plant trees, build bridges across rivers in forests, and so on. In a small town in the United States a large group of girls cleaned the banks of 11 kilometers of their river. Young people may hear about conservation through something called “No one’s going to change our world”, which was made by the Beatles, Cliff Richard and other singers. The money from it will help to conserve wild animals.

1. What does the word “conserve” in the passage mean?

A．serve

B．protect

C．live

D．desert

2. The first paragraph tells us that _______.

A．World Conservation Year was over.

B．animals are being in danger

C．nature is being destroyed in Holland

D．the people of the world face the serious living situation

3. “No one’s going to change our world” was _______.

A．a record calling on people to conserve nature

B．an idea that nobody would accept

C．an important book published in 1970

D．a rule worked out by the United Nations

4. What is the most important thing for us to do to save our world?

A．We should plant more trees and flowers.

B．We should clean the banks of our rivers.

C．We should know what we must do and begin to do it now.

D．We should know what will happen in the future.

5. What’s the main idea of the passage?

A．1970 was an important year.

B．The United Nations wanted everyone to know that the world is in danger.

C．Conservation is necessary.

D．It is the young people who are helping to save our world.

9 . These days a green building means more than just the color of the paint. Green building can also refer to environmentally friendly houses, factories, and offices.

Green building means “reducing the impact (影响) of the building on the land”, Taryn Holowka of the U.S. Green Building Council in Washington, D.C., said.

According to Holowka, building accounts for (占了) 65 percent of total U.S. electricity use.   

But green building can reduce energy and water use. Also, the building are often located near public transportation such as buses and subways, so that people can drive their cars less. That could be good for the environment, because cars use lots of gas and give off pollution. Green building are often built on developed land, so that the buildings don’t destroy forests.

Marty Dettling is project manger for a building that put these ideas into action . The Solaire has been called the country’s first green high-rise building. According to Dettling, “We’ve reduced our energy use by one-third and our water by 50 percent,”

The Solaire cuts energy in past by using solar power. “ On the face of the building we have solar panels which change the sun’s energy into electricity,” Dettling explained.

The Solaire also has lights that automatically turn off when people leave the room. In addition, the building has lots of windows, allowing people to use the sun for light during the day. The Solaire cuts water reusing it.

Not everyone is eager to move into a green building, however. Some people think that things like solar panels cost more money than more traditional energy sources. Anyhow, Holowka said, “It’s going to be big.”

1. In the second paragraph, the underlined words “the building” most probably refer to ____.

A．an ordinary building	B．an energy-saving building
C．a green-colored building	D．a building in Washington D.C.

2. A green building is often built on an area of land______.

A．which has thick forests around

B．which has already been for buildings

C．where people of high income live

D．where traveling around by car is most convenient

3. When Holowka says in the last paragraph, “It’s going to be big”, she means that green buildings_____.

A．will be more comfortable

B．will become popular in future

C．will be more environmentally friend

D．will take the place of traditional building

4. When is the main subject discussed in the text?

A．Dettling designed the first green building in the U.S.

B．Energy shortage calls for buildings of new design.

C．Green building help save environment.

D．The Solaire serves as a model of high building.

10 . Where was the man when the earthquake happened?

A．In a hospital

B．In a restaurant.

C．In his bedroom