We already know the fastest, least expensive way to slow climate change: Use less energy. With a little effort, and not much money, most of us could reduce our energy diets by 25 percent or more—doing the Earth a favor while also helping our wallets.

     Not long ago, my wife, PJ, and I tried a new diet—not to lose a little weight but to answer an annoying question about climate change. Scientists have reported recently that the world is bending up even faster than predicted only a few years ago, and that the consequences could be severe if we don't keep reducing emissions(排放) of carbon dioxide (CO₂ ) and other greenhouse gases that are trapping heat in our atmosphere.

     We decided to try an experiment. For one month we recorded our personal emissions of CO₂ . We wanted to see how much we could cut back, so we went on a strict diet. The average US household(家庭) produces about 150 pounds of CO₂  a day by doing common-place things like turning on air-conditioning or driving cars. That's more than twice the European average and almost five times the global average, mostly because Americans drive more and have bigger houses. But how much should we try to reduce?

        For an answer, I checked with Tim Flannery, author of The Weather Makers: How Man is Changing the Climate and What it Means for Life on Earth. In his book, he had challenged readers to make deep cuts in personal emissions to keep the world from reaching extremely important tipping points, such as the melting(融化) of the ice sheets in Greenland or West Antarctica. "To stay below that point, we need to reduce CO₂  emissions by 80 percent," he said.

        Good advice, I thought. I'd opened our bedroom windows to let in the wind. We'd gotten so used to keeping our air-conditioning going around the clock. I'd almost forgotten the windows even opened. We should not let this happen again. It's time for us to change our habits if necessary.

21.Why did the author and his wife try a new diet?

   A. To take special kinds of food. B. To respond to climate change.

   C. To lose weight.           D. To improve their health.

22.The underlined words "tipping points" most probably refer to                 .

   A. freezing points  B. burning points

   C. melting points   D. boiling points

23.It can be inferred from the passage that                 .

   A. it is necessary to keep the air-conditioning on all the time

   B. it seems possible for every household to cut emissions of CO2

   C. the average US household produces about 3,000 pounds of CO2 a month

   D. the average European household produces about 1,000 pounds of CO2 a month

    Long-time exposure to air pollution can lead to physical changes in the brain and cause trouble in learning and memory, and even anxiety. This is suggested by the results of new research on mice.

    While other studies have shown the harmful effects of polluted air in the lungs and heart, this is the first to show the negative effect on the brain.

     The team of Laura Fonken, Randy Nelson, from the Ohio State University, USA, has spread to the brain a previous line of research which found that fine particulate (微粒) matter floating in the air mainly because of air pollution caused by humans, causes swelling in much of the body, and may be related to high blood pressure problems, and some other diseases.

     In the research Fonken and his colleagues exposed mice to polluted air for six hours each day, five days a week, over a period of 10 months, almost half the average life length of mice.

     Polluted air contains fine particles created by cars, factories and natural dust. Fine particles of this kind are tiny, about 2.5 micrometers in diameter, or about one-thirtieth the width of a human hair. These particles can go deep into lungs and other organs.

     The concentration of this particulate material to which they exposed mice is equal to the concentration at which people can be exposed in some polluted urban areas.

     After a period of 10 months, the researchers got the animals to have a series of behavioral tests. Both the behavior of mice and the results of neurological(神经的) tests done to them show that those within the polluted air had more problems in learning and memory, and higher levels of anxiety.

     The results suggest that long-time exposure to polluted air can have measurable negative effects on the human brain and can cause a variety of mental health problems. This could have important consequences for those living and working in polluted urban areas.

24.The results of new research on mice first suggest that polluted air mainly does harm to                 .

   A. normal organs     B. lungs and heart      C. mental health   D. blood pressure

25. The bad effects of tiny particles in polluted air are those except                 .

   A. high blood pressure problems         B. making human hair thinner

   C. different kinds of diseases          D. swelling in much of the body

26. From the last sentence we can infer that people living in polluted urban areas                 .

   A. are likely to suffer from mental problems     B. can measure the negative effect on them

   C. show little concern for air pollution          D. can be exposed to polluted air longer

27. Which of the following is the best title for the passage?

   A. Long-time Exposure to Air Pollution        B. Evidence and Concern of Air Pollution

   C. Measurable Effect on Human Brain         D. Mental Problems Caused by Air Pollution

    Tuvalu, a tiny country in the Pacific Ocean, has asked for help as it fears it will be swallowed up by the sea.

    Storms and huge waves are a constant threat and none of Tuvalu's nine little islands is more than five metres above sea level. Salt water is already entering the country's drinking water supply, as well as damaging plants that produce fruit and vegetable. Without urgent help, the country's days are numbered.

    But Tuvalu is not the first place to face sinking into the sea. Venice, a historic city in Italy best known for its canals, has sunk about 24 cm over the past 100 years. Experts say that it will have sunk another 24 cm by 2050. A century ago, St. Mark's Square, the lowest point in the city, flooded about nine times a year. Nowadays, it happens more than 100 times. While Venice is slowly sinking into the mud on which it stands, Tuvalu's rising sea level is caused by global warming.

     The average global temperature has increased by almost 0. 5 centigrade degrees over the past century, scientists expect it to rise by extra 1.3 degrees over the next 100 years.

     Warmer weather makes glaciers(冰川) melt, adding more water to the ocean. The warmer temperatures also make water expand, so it takes up more space, causing the sea level to rise. The sea level has risen 10.25 cm in the last 100 years.

     The main cause of global warming is human pollution. Through burning coal, oil and gas, people have been increasing the greenhouse gases in the atmosphere, such as CO2. This adds to the power of the greenhouse effect, making the planet even warmer.

    Many scientists believe that, if the warming is not stopped, there will be huge climate changes. The sea level could rise by one meter this century.

    Should this come true, the sea will swallow up millions of homes and the world will be flooded with "climate refugees" looking for somewhere to live.

28. We can infer from the second paragraph that                 .

   A. Tuvalu is in danger of being swallowed up by the sea

   B. all Tuvalu's islands are about five metres above the sea level

   C. drinking water in Tuvalu has been destroyed

   D. Tuvalu is often flooded by storms and waves

29.The author uses Tuvalu and Venice as examples in order to explain                 .

   A. they are the first places sinking into the sea  B. they are both sinking into the mud where they stand

   C. they will disappear in the future           D. their trouble is caused by global warming

30.What does "climate refugees" mean?

   A. People who are forced away from their homeland by climate. B. Climate changes.

   C. Rare animals.                                      D. Climate effect.

31.Which of the following is NOT true according to the passage?

   A. Tuvalu's nine little islands are less than five meters above the sea level.

   B. The average global temperature has risen by 13 centigrade degrees over the past 100 years.

   C. The warmer temperature causes the sea level to rise.

   D. There will be huge climate changes unless the warming is stopped.

Research shows that childhood friendships are important indicators of future success and social adjustment. Children’s relationships with peers (同龄人) strongly influence their success in school，and children with fewer friends are more at risk of dropping out of school，becoming depressed and other problems.

Making and Keeping Friends Is More than Child’s Play

When 6­year­old Rachel returned to school on a recent Monday morning，her eyes immediately  scanned the playground for her friend Abbie. “Though they were only separated by a weekend，the girls ran right into each other’s arms and hugged,” recalls Rachel’s mother Kathryn Willis of Gilbert. “It was like a scene from a movie.”

Most parents instinctively (本能地) know that having friends is good for their child. Experts agree that friendship is not simply child’s play，but a powerful predictor of social adjustment throughout life.

A Skill for Life

“Childhood friendships serve as a very important training ground for adulthood,” says  Dr.Robbie Adler­Tapia，psychologist with the Center for Children’s Health & Life Development at the East Valley Family Resource Center.

Researcher William Hartup states，“Peer relations contribute significantly to both social and cognitive (认知的) development.” Hartup concludes that the single best childhood predictor of adult social adaptation is not school grades or classroom behavior，but rather，how well a child gets along with other children.

The work of Arizona State University professor of Developmental Psychology Gary Ladd proves that being able to make and keep friends is beneficial to kids while the lack of friends is detrimental.

Good Friendships Don’t Just Happen

Experts agree that it is essential for children to establish high­quality friendships. But，researchers  warn，these friendships don’t necessarily just happen. Often，a good friendship begins with involved parents.

Psychologist Dr.Lynne Kenney Markan believes kids should be taught social skills in much the same way they are taught math and reading.

Bad Company

Many parents worry about the quality as well as the quantity of their child’s friendships. “When she was in 1st grade，her supposed ‘best friend’ began calling her names and threatening to hurt her,” says Mindy Miller. “My daughter wasn’t allowed to talk to or even look at other girls in her class. It really crushed her spirit. I told my daughter she didn’t need a ‘friend’ like that.”

“I’ll bend over backwards(拼命) to help my son get together with a friend I think is good for him,” Adler­Tapia says. “I don’t look at it as manipulation (操纵)，just positive parental involvement.”

32. The example of Rachel and Abbie is used to indicate that________.

A. childhood friendship is of great significance to their growth

B. a positive friendship helps children solve emotional and physical problems

C. it is a proven fact that peer friendship is the most rewarding experience throughout life

D. Rachel missed her friend Abbie very much because of their separation of one weekend

33.The underlined word “detrimental” could be replaced by________.

A. aggressive　    B. disappointing    C. ridiculous　　    D. harmful

34.We can learn from the passage that high­quality friendship most probably results from______.

A. social skills and good study habits       B. school grades and classroom behaviors

C. academic success and social adaptation   D. positive parental involvement and social skills

35. From the last paragraph we can conclude that Dr.Robbie Adler­Tapia agrees that________.

A. parents should regard making friends as something that just happens

B. it’s wise for parents to support and encourage healthy peer relationships

C. parents only need to help their children to cope with difficult social situations

D. parents are supposed to encourage their children to make as many friends as they can

        Do you want to take time to get in touch with yourself, your feelings, your dreams, and a good, healthy life? Here are some tips:

        36.                 Sometimes it seems as if our culture has begun to view the need for sleep as a sign of weakness. But your body was genetically(基因地) programmed to spend a third of its life on sleep, and this affects thinking, memory, growth, your immune(免疫的) system and even your weight.

        Begin the day in thankfulness. 37                 Name each person and hold them in your thoughts. The sense of thankfulness you experience will set a peaceful tone for the entire day, and reduce a day's stress that can lead to sleeplessness that night.

        Strike a balance. 38.                 Think about tai chi, prayer, yoga(瑜伽)—any daily activity that allows you to develop a peaceful center and a sense of balance.

        Play with friends. The "tend and be friend studies", as they are called, conducted by UCLA researcher, Shelly Taylor, Ph.D. indicate that when women are stressed, they tend to their children and play with other women. 39                

        Use guided imagination. 40                 The tone of your voice, pacing, music, and pictures will persuade your nervous system that it's time to calm down.

   A. Admit the importance of sleep.

   B. The images of things make the brain see and think about other things.

   C. Emotions are the basis of good communications and healthy relationships.

   D. Calming down a stressed nervous system will encourage a balanced life.

   E. Take 10 minutes every morning to give thanks to everyone in your life.

   F. Recent research has also linked the importance of sleep to behavior.

   G. Studies reveal(揭示) that women who have healthy relationships with their children and friends actually sleep better.