单选题The view from my bedroom window was absolutely spectacular .

单选题I know you have made all the {{U}}arrangements{{/U}} for the conference.

单选题Eat More, Weigh Less, Live Longer Clever genetic detective work may have found out the reason why a near-starvation diet prolongs the life of many animals. Ronald Kahn at Harvard Medical School in Boston, U.S., and his colleagues have been able to extend the lifespan (寿命) of mice by 18 per cent by blocking the rodent's (啮齿动物) increase of fat in specific cells. This suggests that thinness--and not necessarily diet--promotes long life in "calorie (热量卡) restricted" animals. "It's very cool work," says aging researcher Cynthia Kenyon of the University of California, San Francisco. "These mice eat all they want, lose weight and live longer. It's like heaven." Calorie restriction dramatically extends the lifespan of organisms as different as worms and rodents. Whether this works in humans is still unknown partly because few people are willing to submit to such a strict diet. But many researchers hope they will be able to trigger the same effect with a drug once they understand how less food leads to a longer life. One theory is that eating less reduces the increase of harmful things that can damage cells. But Kahn's team wondered whether the animals simply benefit by becoming thin. To find out, they used biology tricks to disrupt the insulin (胰岛素) receptor (受体) gene in lab mice, but only in their fat cells. "Since insulin is needed to help fat cells store fat, these animals were protected against becoming fat," explains Kahn. This slight genetic change in a single tissue had dramatic effects. By three months of age, Kahn's modified mice had up to 70 per cent less body fat than normal control mice, despite the fact that they ate 55 per cent more food per gram of body weight. In addition, their lifespan increased. The average control mouse lived 753 days, while the thin rodents averaged a lifespan of 887 days. After three years, all the control mice had died, but one-quarter of the modified rodents were still alive. "That they get these effects by just manipulating the fat cells is controversial," says Leonard Guarente of the Massachusetts Institute of Technology, who studies calorie restriction and aging. But Guarente says Kahn has yet to prove that the same effect is responsible for increased lifespan in calorie-restricted animals. "It might be the same effect or there might be two routes to long life," he points out, "and that would be very interesting./

单选题I will take up teaching this September.A. startB. get offC. captureD. pick up

单选题Having worked hard for a whole week, I am looking forward to the weekend.

单选题In a bullfight, it is the movement, not the color, of objects that arouses the bull.

单选题Once Daily Pill Could Simplify HIV Treatment Bristol-Myers Squibb and Gilead Sciences have combined many HIV drugs into a single pill. Sometimes the best medicine is more than one kind of medicine. Malaria, tuberculosis and HIV/AIDS, 1 , are all treated with combinations of drugs. But that can mean a lot of pill to take. It would be 2 drug companies combined all the medicines into a single pill, taken just once a day. Now, two companies say they have done that for people just 3 treatment for HIV, the virus that causes AIDS. The companies are Bristol-Myers Squibb and Gilead Science. They have 4 a single pill that combines three drugs currently on the market. Bristol-Myers Squibb sells one of them 5 the name of Sustiva. Gilead combined the 6 , Emtriva and Viread, into a single pill in two thousand four. Combining drugs involves more than 7 issues. It also involves issues of competition 8 the drugs are made by different companies. The new once-daily pill is the result of 9 is described as the first joint venture agreement of its kind in the treatment of HIV. In January the New England Journal of Medicine published a study of the new pill. Researcher compared its 10 to that of the widely used combination of Sustiva and Combivir. Combivir 11 two drugs, AZT and 3TC. The researchers say that after one year of treatment, the new pill suppressed HIV levels in more patients and with fewer 12 effects. Gilead paid for the study. Professor Joel Gallant at the Johns Hopkins School of Medicine in Baltimore, Maryland, led the research. He is a paid adviser to Gilead and Bristol-Meyers Squibb as well as the maker of Combivir, Glaxo Smith Kline. Glaxo Smith Kline reacted 13 the findings by saying that a single study is of limited value. It says the effectiveness of Combivir has been shown in each of more than fifty studies. The price of the new once-daily pill has not been announced. But Gilead and Bristol-Myers Squibb say they will provide it at reduced cost to developing countries. They plan in the next few months to ask the United States Food and Drug Administration to approve the new pill. There are limits to who could take it 14 the different drugs it contains. For example, 15 women are told not to take Sustiva because of the risk of birth disorders. Experts say more than forty million people around the world are living with HIV.

单选题Swedish is the {{U}}native{{/U}} language of most Swedes.

单选题We consume a lot more than we are able to produce. A. waste B. buy C. use D. sell

单选题Noise Pollution Psychologists now believe that noise has a considerable effect on people's attitudes and behavior. Experiments have proved that in noisy situations (even temporary ones), people would have more irritability (躁易怒) and less cooperation. In more permanent noisy situations, many people cannot work hard, and they suffer from severe anxiety as well as other psychological problems. Some researchers, who study various aspects of effect of noise in people's mental life, maintain that noise, either temporary noise or permanent noise, often destroy creativity and activity by disturbing people's emotion and make them more irritable and hard to cooperate. However, psychologists distinguish between "sound" and "noise". "Sound" is measured physically in decibels (分贝). "Noise" cannot be measured in the same way because it refers to the psychological effect of sound and its level of "intensity" depends on the situation. Thus, for passengers at an airport who expect to hear airplanes taking off and landing, there may be a lot of sound, but not much noise (that is, they are not bothered by the noise). By contrast, if you are at a concert and two people behind you are whispering, you feel they are talking noisily even if there is not much sound. You notice the noise because it affects you psychologically. Both sound and noise can have negative effects, but what is most important is if the person has control over the sound. People walking down the street with earphones, listening to music that they enjoy, are receiving a lot of decibels of sound, but they are probably happy hearing sounds which they control. On the other hand, people in the street without earphones must tolerate a lot of noise which they have no control over. It is noise pollution that we need to control in order to help people live more happily.

单选题He spoke so quickly that it was difficult to take down what he was saying.

单选题These are their motives for doing it A. reasons B. excuses C. answers D. plans

单选题All the changes that have {{U}}overtaken{{/U}} Shetland recently.

单选题The firm of Bonnin and Morris in Philadelphia was probably the first American company to manufacture porcelain.A. silverwareB. crystalC. chinaD. linen

单选题 阅读下面这篇短文，短文后列出7个句子，请根据短文的内容对每个句子做出判断。 {{B}} On British Newspapers{{/B}} Besides the daily newspapers, there are a number of Sunday newspapers in Britain. Many of them are connected with the "dailies", though not run by the same editor and his members. The Sunday papers are larger than the daily papers and usually contain more articles concerned with comment (评论) and general information rather than news. The national daily and Sun day papers have the largest circulation(发行) in the world. Of the Sunday papers, the Observer and the Sunday Times are the best known. It is a regrettable fact that the number of magazines of a literary or political nature has dropped down since the war. This has probably been caused by the ever-wider use of radio and television. The most successful magazines are those published for women. Their covers are designed to catch the eye, and they certainly succeed in doing so! They offer their readers articles on cookery (烹饪法), fashion, needlework, and many other matters of women interest. They also provide advice to those in love, and adventures with handsome heroes. Some women's magazines also include serious articles of more general interest. The visitor who looks at the magazines displayed in a large bookstall (书摊) which may be found in an important railway station will notice that there is a wide variety of technical or semitechnical(半专业的) books and magazines. There are magazines for the motorist, the farmer, the gardener, the nurse, and many others. There are many local and regional newspapers. It is common in Britain for a news agent(报刊经售人) to deliver (投递) the morning papers to his customers for a small extra payment, this service is usually performed by boys and girls who want to earn some pocket-money.

单选题The government is debating the education laws.

单选题The change in that village was miraculous .

单选题The high-speed trains can have a major U impact/U on our lives．

单选题We have to act within the existing legal framework .

单选题It can be seen from the passage that the earth's supply of natural medicines A. may never be exhausted. B. may be dropping rapidly. C. is surprisingly big. D. is as rich-as ever.