12.We can learn from the passage that    .

A、human life will not last more than 120 years in the future

B、humans have to take medicine to build new skin cells now

C、much needs to be done before humans can have a longer life

D、we have already solved the technical problems in building new cells

D

Among all the malignancies (恶性肿瘤), lung cancer is the biggest killer: more than 10,000 Americans die of the disease a year. Giving up smoking is one of the obvious ways to reduce the risk, but another answer may lie in the kitchen. According to a new report, even heavy smokers may be protected from developing lung cancer by a simple dietary measure: a daily portion of carrots, spinach or any other vegetable or fruit containing a form of vitamin A called carotene (胡萝卜素).

The finding, published in the British medical journal The Lancet, is a part of a long-range investigation of diet and disease. Since 1957 a team of American researchers has monitored the dietary habits and medical histories of 2,000 middle-aged men employed by the Western Electric Co. in Chicago. Led by Dr Richard Shekelle of Chicago’s Rush-Presbyterian-St. Luke’s Medical Center, the researchers recently began to sort out the links between the subjects’ dietary patterns and cancer. Other studies of animals and humans have suggested that vitamin A offers some protection against lung cancer. The connection seems logical, explains Shekelle, since vitamin A is essential for the growth of the epithelial (上皮的) tissue that lines the airways of the lungs.

But the earlier research did not distinguish between two different forms of the vitamin. Preformed vitamin A is found mainly in liver and dairy products like milk, cheese, butter and eggs. But vitamin A is also made in the body from carotene, which is abundant in a variety of vegetables and fruits, including carrots, spinach, squash (南瓜), tomatoes, sweet potatoes and apples.

In the Western Electric study, Shekelle and his colleagues found few connections between the incidence of lung cancer and the consumption of foods containing preformed vitamin A. But when they examined the data on carotene intake, they discovered a significant relationship. Among the 488 men who had the lowest level of carotene consumption, there were fourteen cases of lung cancer; in a group of the same size that ate the most carotene, only two cases developed. The apparent protective effect of carotene helps even longtime smokers, but to a lesser degree.

Further studies will be necessary before the links between lung cancer and carotene can be firmly established. In the meantime, researchers warn against large numbers of vitamin A pills, because the tablets contain a form of the chemical that can be extremely poisonous in high doses. Instead, they advise a well-balanced diet that includes foods rich in carotene. For a smoker, half a cup of carrots every day might make the difference between life and death.

13. Which of the following might be most helpful for people to avoid getting lung cancer?

A. Eating vegetables containing carotene every day.

B. Giving up smoking right now.

C. Eating more fresh fruits every day.

D. Eating a simple everyday diet.

14. From Paragraph 2 we can learn that ________.

A. Shekelle has been researching lung cancer since 1957

B. the links between diet and lung cancer were discovered by Shekelle himself

C. Shekelle got the finding after monitoring 2,000 men for many years

D. the researchers have investigated the relationship between diet and disease for half a century

15. The examinations on groups of people of the same size showed that ________.

A. few people got lung cancer because most of them have a well-balanced diet

B. the incidence of lung cancer is closely related to the intake of carotene

C. the intake of carotene has little protective effect on longtime smokers

D. the result of the earlier research is false and of no use

II. 完形填空(30分)

In our discussion with people on how education can help them succeed in life, a woman remembered the first meeting of an introductory__16__course about 20 years ago.     The professor __17__the lecture hall, placed upon his desk a large jar filled with dried beans(豆), and invited the students to _18_how many beans the jar contained. After __19__shouts of wildly wrong guesses the professor smiled a thin, dry smile, announced the __20__ answer, and went on saying, ”You have just __21__an important lesson about science. That is Never__22__ your own senses.”     Twenty years later, the __23__could guess what the professor had in mind. He __24__himself, perhaps, as inviting his students to start an exciting __25__into an unknown world invisible(无形的)to the  26  ,which can be discovered only through scientific  27  . But the seventeen-year-old girl could not accept or even  28  the invitation. She was just 29  to understand the world. And she   30   that her firsthand experience could be the  31   .The professor, however, said that it was  32   .He was taking away her only 33 for knowing and was providing her with no substitute. “I remember feeling small and 34 ,”the women says, “and I did the only thing I could do. I  35  the course that afternoon, and I haven’t gone near science since.”

16.A.art  B.science  C.history  D.math

17.A.looked at  B.searched for    C.got through D.marched into

18.A.count  B.guess  C.report  D.watch

19.A.warning  B.turning away C.giving  D.listening to

20.A.ready  B.correct  C. Difficult        D.possible

21.A.prepared  B.taught  C.Taken         D.Learned

22.A.trust  B.sharpen  C.Show         D.lose

23.A.lecturer  B.speaker  C.Woman         D.Scientist

24.A.described  B.respected  C.saw  D.served

25.A.movement   B.change  C.Rush          D.Voyage

26.A.eye   B.knowledge   C.Light          D.professor

27.A. senses  B.spint   C.Methods       D.model

28.A.make  B.present     C.Refuse         D.hear

29.A.suggesting B.pretending      C.Waiting        D.beginning

30.A.doubted  B.proved  C.Explained      D.believed

31.A.growth  B.faith    C.Truth          D.strength

32.A.firm   B.interesting C.wrong    D.acceptable

33.A.task    B.tool          C.success  D.connection

34.A.cruel    B.proud   C.frightened  D.brave

35.A.dropped   B.started    C.passed   D.missed

III. 任务型阅读(七选五，10分)