LONDON----Here’s a new warning from health experts: Sitting is deadly.

     Scientists are increasingly warning that sitting for prolonged periods — even if you also exercise regularly — could be bad for your health. And it doesn’t matter where the sitting takes place — at the office, at school, in the car or before a computer or TV — just the overall number of hours it occurs. Several studies suggest people who spend most of their days sitting are more likely to be fat, have a heart attack or even die.

　　In an editorial published this week in the British Journal of Sports Medicine, Elin EkblomBak of the Swedish School of Sport and Health Sciences suggested that authorities rethink how they define physical activity to highlight the dangers of sitting.

　　While health officials have issued guidelines recommending minimum amounts of physical activity, they haven’t suggested people try to limit how much time they spend in a seated position.

　　"After four hours of sitting, the body starts to send harmful signals," Ekblom-Bak said. She explained that genes regulating(调节) the amount of glucose（葡萄糖） and fat in the body start to shut down.

　　Even for people who exercise, spending long periods of time sitting at a desk is still harmful. Tim Armstrong, a physical activity expert at the World Health Organization, said people who exercise every day — but still spend a lot of time sitting — might get more benefit if that exercise were spread across the day, rather than in a single bout.（一回）

　　Still, in a study published last year that tracked more than 17,000 Canadians for about a dozen years, researchers found people who sat more had a higher death risk, independently of whether or not they exercised.

　　"We don’t have enough evidence yet to say how much sitting is bad," said Peter Katzmarzyk of the Pennington Biomedical Research Center in Baton Rouge, who led the Canadian study. "But it seems the more you can get up and interrupt this sedentary behavior, the better."

　　Figures from a U.S. survey in 2003-2004 found Americans spend more than half their time sitting, from working at their desks to sitting in cars.

　　Experts said more research is needed to figure out just how much sitting is dangerous, and what might be possible to offset those effects.

　　"People should keep exercising because that has a lot of benefits," Ekblom-Bak said. "But when they’re in the office, they should try to interrupt sitting as often as possible," she said.

1.What is the best title for the text?

A. Not Sitting Too Much While Working      B. How To Avoid Sitting Too Much

C. Sitting Too Much Could Be Deadly          D. More And More People Sit Too Much

2.According to the research,______________.

A. the more time you spend in exercising in a single bout, the healthier you will be.

B. those who often sit too much are sure to grow fat or suffer from a heart attack.

C. regular exercise is effective to get rid of the side effect of sitting too much.

D. you had better not sit for more than four hours in a single bout.

3.How does the danger of sitting too much affect the human body?

A. It results in a higher death risk.

B. It increases glucose and fat in the body.

C. It makes a person unable to exercise long enough in a day.

D. It causes the gene to fail to balance the glucose and fat in the body.

4.In the opinion of Ekblom-Bak, you’d better have a rest in the office by________.

A. sending your friends e-mails           

B. having a walk around your office

C. chatting online or playing computer games 

D. listening to music with your head on the desk.

阅读下面短文，掌握其大意，然后从各题所给的四个选项（A、B、C和D）中，选出最佳选项。

There are many kinds of friends. Some are always ___1___you, but don't understand you. Some say only a few words to you, but understand you. Many people will step in your life, but only ___2___friends leave footprints (脚印).

　　I shall always recall (回忆) the autumn and the girl with the ___3___ . She will always bring back the friendship between us. I know she will always be my best friend.

　　It was the golden season. I could see the yellow leaves ___4___  on the cool ___5___. In such a season, I liked walking alone in the leaves, ____6__ to the sound of them.

　　Autumn is a __7____ season and life is uninteresting. The free days always get me ___8___ . But one day, the sound of a violin  __9____into my ears like a stream (小溪) flowing in the mountains. I was so surprised that I jumped to see what it was. A young girl, standing in the wind, was__10____ in playing her violin.

　　I had __11____ seen her before. The music was so nice that I listened quietly. Lost in the music, I didn't know that I had been ___12___ there for so long but my existence (存在) did not seem to disturb her.

　　Leaves were still falling. Every day she played the violin in the corner of the building  ___13___ I went downstairs to watch her performance. I was the only listener. The autumn seemed no longer lonely and life became ___14___.  __15____ we didn't know each other, I thought we were already good friends. I believe she also loved me.

　　Autumn was nearly over. One day, when I was listening carefully, the sound suddenly ___16___. To my astonishment (惊讶), the girl came over to me.

　　“You must like violin.” she said.

　　“Yes. And you play very well. Why did you stop?” I asked.

　　Suddenly, a __17____ expression appeared on her face and I could feel something unusual.

　　“I came here to see my grandmother, but now I must leave. I once played very badly. It was your listening every day that _18_____ me.” she said.

　　“In fact, it was your playing _19_____ gave me a meaningful autumn,” I answered, “Let's be friends.”

　　The girl smiled, and so did I.

　　I never heard her play again in my life. I no longer went downstairs to listen like before. Only thick leaves were left behind. But I will always remember the fine figure (身影) of the girl. She is like a __20____—so short, so bright, like a shooting star giving off so much light that it makes the autumn beautiful.

1..

2..

There are many kinds of friends. Some are always    36   you, but don't understand you. Some say only a few words to you, but understand you. Many people will step in your life, but only   37  friends leave footprints.

　　I shall always recall (回忆) the autumn and the girl with the  38  . She will always bring back the friendship between us. I know she will always be my best friend.

　　It was the golden season. I could see the yellow leaves   39  on the cool  40 . In such a season, I liked walking alone in the leaves,  41   to the sound of them.

　　Autumn is a  42   season and life is uninteresting. The free days always get me   43  . But one day, the sound of a violin   44   into my ears like a stream (小溪) flowing in the mountains. I was so surprised that I jumped to see what it was. A young girl, standing in the wind, was  45   in playing her violin.

　　I had  46  seen her before. The music was so nice that I listened quietly. Lost in the music, I didn't know that I had been   47  there for so long but my existence (存在) did not seem to disturb her.

　　Leaves were still falling. Every day she played the violin in the corner of the building  48  I went downstairs to watch her performance. I was the only listener. The autumn seemed no longer lonely and life became   49  .  50  we didn't know each other, I thought we were already good friends. I believe she also loved me.

Autumn was nearly over. One day, when I was listening carefully, the sound suddenly

   51  . To my astonishment (惊讶), the girl came over to me.

　　“You must like violin.” she said.

　　“Yes. And you play very well. Why did you stop?” I asked.

　　Suddenly, a   52  expression appeared on her face and I could feel something unusual.

　　“I came here to see my grandmother, but now I must leave. I once played very badly. It was your listening every day that   53  me.” she said.

　　“In fact, it was your playing   54  gave me a meaningful autumn,” I answered, “Let's be friends.”

　　The girl smiled, and so did I.

I never heard her play again in my life. I no longer went downstairs to listen like before. Only thick leaves were left behind. But I will always remember the fine figure (身影) of the girl. She is like a   55 —so short, so bright, like a shooting star giving off so much light that it makes the autumn beautiful.

Sometimes people come into your life ．You know that they will help you　 out who you

are or who you want to become·You never know 　 these people may be，possibly your roommate，neighbor，or even a complete stranger．But when you　 eyes with them，you know at that very moment they will　 　your life in some way．

??? And sometimes things happen to you that may seem　 at first，but in reflection you find that without them you would have never　 your potential ability．

??? Everything happens for a　 　．Nothing happens by chance or　 good luck．Illness，injury，love all occur to test the　 of your soul．Without these small tests，life would be like? a　 road to nowhere ．The people affecting your life，and the　 and failure you experience，help to create who you are and who you become．? 　 the bad experiences can be learned from，for they are　 the most important ones·If someone loves you，love them back unconditionally，because they are　 you to love．If someone hurts you，　 them，for they have helped you learn about　 and the

importance of being cautious．

??? Make every day 　 ．Appreciate every moment，for you may never be able to 53 it again·Tell yourself you are a great individual and　 yourself. Create your own life and then go out and live it with absolutely no　 ． Most importantly，if you LOVE someone，tell him or her，for you never know what tomorrow

may have in store．

1.A. figure 　???? B. take 　??? C. give 　??? D. speak

2.A. where　????? B．how 　?? C．who 　?? D. what

3.A．fill 　?????? B．lock　　? C．cover 　? D. close

4.A．value 　??? B．affect 　?? C．love 　?? D．waste

5.A. exciting 　?? B. inspiring 　 C. inviting 　? D. challenging

6.A. realized 　??? B.lacked 　?? C．controlled D. tested

7.A. profit 　???? B. fact 　????? C. reason 　? D. result

8.A. in need of 　 B. on behalf of 　C. on account of D. by means of

9.A. degrees 　?? B. limits 　???? C. influence 　D. condition

10.A. smooth 　?? B. snowy 　??? C. busy 　?? D. heavy

11.A. sense 　??? B. incident 　?? C. success 　 D. feeling

12.A. So　??????? B. Yet　?????? C. Thus 　?? D．Even

13.A. probably　?? B. exactly 　? C. certainly 　D. rarely

14.A. persuading 　B. allowing??? C. teaching 　D. forcing

15.A. warn ????? B. forgive 　?? C. scold　 ?? D. charge

16.A. agreement? B. society 　??? C. right 　?? D. trust

17.A. count 　? B. mean 　???? C. go ??????? D. change

18.A. save 　??? B. experience 　C. share 　D. miss

19.A. hold on 　 B. care for 　?? C. think of 　D. believe in

20.A. efforts 　? B. beliefs 　??? C. regrets 　D. directions

For many years, scientists couldn't figure out how atoms and molecules on the Earth combined to make living things. Plants, fish, dinosaurs, and people are made of atoms and molecules, but they are put together in a more complicated way than the molecules in the primitive ocean. What's more, living things have energy and can reproduce, while the chemicals on the Earth 4 billion years ago were lifeless.
　　After years of study, scientists figured out that living things, including human bodies, are basically made of amino acids and nucleotide bases. These are molecules with millions of hydrogen, carbon, nitrogen, and oxygen atoms. How could such complicated molecules have been formed in the primitive soup? Scientists were stumped.
　　Then, in 1953, two scientists named Harold Urey and Stanley L. Miller did a very simple experiment to find out what had happened on the Primitive Earth. They set up some tubes and bottles in a closed loop, and put in some of the same gases that were present in the atmosphere 4 billion years ago: water vapor, ammonia, carbon dioxide, methane, and hydrogen.
　　Then they shot an electric spark through the gases to simulate bolts of lightning on the ancient Earth, circulated the gases through some water, sent them back for more sparks, and so on. After seven days, the water that the gases had been bubbling through had turned brown. Some new chemicals were dissolved in it. When Miller and Urey analyzed the liquid, they found that it contained amino acids-the very kind of molecules found in all living things.
61. When did scientists come to realize how the atoms and molecules on the Earth combined to make living thing?
　　A. 4 billion years ago. B.1953.　C. After seven days.D. Many years later.
62. Scientists figured out that human bodies are basically made of .
A.amino acids
B.molecules
C. hydrogen, carbon, nitrogen and oxygen atoms
D. water vapor, ammonia, carbon dioxide, methane and hydrogen
63. Harold Urey and Stanley L.Miller did their experiment in order to .　
A. find out what had happened on the Earth 4 billion years ago
　　 B.simulate bolts of lightning on the ancient Earth
　　 C. dissolve some new chemicals
　　D.analyze a liquid
64. At the end of the last paragraph, the underlined word "it" refers to .
A. a closed loop   B. an electric spark   C.water   D. the liquid
65. According to the writer, living things on the Earth include .
　A. atoms and molecules                     B.chemicals　
C. plants, fish, dinosaurs and human beings     D.the primitive soup