单选题 阅读下面的短文，文中有15处空白；每处空白给出4个选项，请根据短文的内容从4个选项中选择1个最佳答案。 Only three strategies are available for controlling cancer, prevention, screening and treatment. Lung cancer causes more deaths than any other type of cancer. A major cause of the disease is{{U}} (51) {{/U}}known; there is no good evidence that screening is of much help; and treatment fails in about 90 per cent of all cases. At present, therefore, the main strategy must be{{U}} (52) {{/U}}. This may not always be true, of course, as for some other types Of cancer, research{{U}} (53) {{/U}}the past few decades has produced (or suggested) some important progress in prevention, screening or treatment.{{U}} (54) {{/U}}, however, we consider not what research may one day offer but what today's knowledge could already deliver that is not being delivered, then the most practicable and cost-effective opportunities for avoiding premature death from cancer, especially lung cancer, probably involve neither screening nor improved{{U}} (55) {{/U}}, but prevention. This conclusion does not depend on the unrealistic assumption that we can{{U}} (56) {{/U}}tobacco. It merely assumes that we can reduce cigarette sales appreciably by raising prices or by{{U}} (57) {{/U}}the type of education that already appears to have had a{{U}} (58) {{/U}}effect on cigarette consumption by white-collar workers, and that we can substantially reduce the amount of tar delivered per cigarette. The practicability of preventing cancer by such measures applies not only in those countries,{{U}} (59) {{/U}}the US, where, because cigarette smoking has been common for decades, 25～30 per cent of all cancer deaths now involve lung cancer, but also in those where it has become{{U}} (60) {{/U}}only recently. In China, for example, lung cancer{{U}} (61) {{/U}}accounts for only about 510 per cent of all cancer deaths. This is because it may take as much as half a century{{U}} (62) {{/U}}the rise in smoking to increase the incidence of lung cancer. Countries where cigarette smoking is only now becoming widespread can expect enormous increases in lung cancer during the 1990s or early in the next century,{{U}} (63) {{/U}}prompt effective action is taken against the habit--indeed., such increases are already plainly evident in parts of{{U}} (64) {{/U}}. There are four reasons why the prevention of lung cancer is of such overwhelming importance: first, the disease is extremely common, causing more deaths than any other type of cancer now does; secondly, it is generally incurable; thirdly, effective, practicable measures to reduce its incidence are already reliably known; and, finally,{{U}} (65) {{/U}}tobacco consumption will also have a substantial impact on many other diseases.

单选题Sulfur has {{U}}occasionally{{/U}} been found in the earth in an almost pure state. A.regularly B.accidentally C.sometimes D.successfully

单选题A Sunshade for the Planet Even with the best will in the world, reducing our carbon emissions is not going to prevent global warming. It has become clear that even if we take the most strong measures to control emissions, the uncertainties in our climate models still leave open the possibility of extreme warming and rises in sea level. At the same time, resistance by governments and special interest groups makes it quite possible that the actions suggested by climate scientists might not be implemented soon enough. Fortunately, if the worst comes to the worst, scientists still have a few tricks up their sleeves. For the most part they have strongly resisted discussing these options for fear of inviting a sense of complacency that might thwart efforts to tackle the root of the problem. Until now, that is. A growing number of researchers are taking a fresh look at large-scale "geo-engineering" projects that might be used to counteract global warming. "I use the analogy of methadone," says Stephen Schneider, a climate researcher at Stanford University in California who was among the first to draw attention to global warming. "If you have a heroin addict, the correct treatment is hospitalization, and a long rehab. But if they absolutely refuse, methadone is better than heroin." Basically the idea is to apply "sunscreen" to the whole planet. One astronomer has come up with a radical plan to cool Earth; launch trillions of feather-light discs into space, where they would form a vast cloud that would block the sun"s rays. It"s controversial, but recent studies suggest there are ways to deflect just enough of the sunlight reaching the Earth"s surface to counteract the warming produced by the greenhouse effect. Global climate models show that blocking just 1.8 per cent of the incident energy in the sun"s rays would cancel out the warming effects produced by a doubling of greenhouse gases in the atmosphere. That could be crucial, because even the most severe emissions-control measures being proposed would leave us with a doubling of carbon dioxide by the end of this century, and that would last for at least a century more.

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

单选题The Faraday effect was the first {{U}}demonstration{{/U}} of a connection between magnetism and light.

单选题Diabetes Most of the food we eat is turned into glucose for our bodies to use for energy. The pancreas, an organ near the stomach, makes a hormone called insulin to help glucose get into your body cells. When you have diabetes, your body either doesn't make enough insulin or can't use its own insulin well. This problem causes glucose to build up in your blood. You may recall having some of these signs before you found out you had diabetes: ** Being very thirsty. ** Urinating a lot often at night. ** Having unclear vision from time to time. ** Feeling very tired much of the time. ** Losing weight without trying. ** Having very dry skin. ** Having sores that are slow to heal. ** Getting more infections than usual. ** Vomiting. Two main types of diabetes are Type 1 and Type 2. Another type of diabetes appears during pregnancy in some women. It's called gestational diabetes. One out of ten people with diabetes has Type I diabetes. These people usually find out they have diabetes when they are children or young adults. The pancreas of a person with Type 1 makes little or no insulin. People with Type 1 diabetes must inject insulin every day to live. Most people with diabetes have Type 2 diabetes. The pancreas of people with such diabetes keeps making insulin for some time, but the body can't use it well. Most people with Type 2 find out about their diabetes after age 30 or 40. Some risk factors which make people more likely to get Type 2 diabetes are: ** A family history of diabetes. ** Lack of exercise. ** Weighing too much. Diabetes can hurt your eyes, your kidneys, and your nerves. It can lead to problems with the blood circulation in your body. Even your teeth and gums can be harmed. And diabetes in pregnancy can cause special problems.

单选题Stone Hill Mall is different from other malls because it has

单选题 下面的短文有15处空白，请根据短文内容为每处空白确定1个最佳选项。 {{B}}Exercise Cuts Cancer Deaths in Men{{/B}} Men who exercise often are less likely to die from cancer than those who{{U}} (51) {{/U}}, new research published in the British Journal of Cancer revealed yesterday. A team of scientists from the Karolinska Institute in Sweden looked{{U}} (52) {{/U}}the effect of physical activity and cancer risk in 40,708 men{{U}} (53) {{/U}}between 45 and 79. The seven-year study found that men{{U}} (54) {{/U}}walked or cycled for at least 30 minutes a day had a 34 percent lower risk of{{U}} (55) {{/U}}from cancer than the men who did less exercise or nothing at all.{{U}} (56) {{/U}}the period studied, 3,714 men developed cancer and 1,153 died from the disease. The researchers suggest that half an hour's walking{{U}} (57) {{/U}}cycling a day increased survival among these men by 33 percent. The researchers surveyed men from two counties in central Sweden about their lifestyle and the amount of{{U}} (58) {{/U}}activity they were usually doing. They then scored these responses and compared the results{{U}} (59) {{/U}}data on cancer diagn0sis and death officially recorded in a Central cancer registry (登记簿) over a seven-year period. Lead author, Professor Alicja Wolk, said:" These results clearly show for the first time the effect that very simple and basic daily{{U}} (60) {{/U}}such as walking or cycling has in reducing cancer death risk in middle-aged and elderly{{U}} (61) {{/U}}." Dr. Lesley Walker, director of cancer information at Cancer Research UK, said: "This study gives us a clear indication that men who exercise are less{{U}} (62) {{/U}}to die from cancer, and that they are more likely to{{U}} (63) {{/U}}the disease if they get it. It's not entirely clear from this study what role exercise plays in preventing{{U}} (64) {{/U}}in men, but we do know that a healthy lifestyle can prevent up to half of all cancers—and{{U}} (65) {{/U}}exercise forms a key part of this."

单选题下面的短文后列出了7个句子，请根据短文的内容对每个句子做出判断：如果该句提供的是正确信息，请选择A；如果该句提供的是错误信息，请选择B；如果该句的信息文中没有提及，请选择C。 {{B}}Easy Learning{{/B}} Students should be jealous. Not only do babies get to doze their days away, but they've also mastered the fine art of learning in their sleep. By the time babies are a year old, they can recognize a lot of sounds and even simple words. Marie Cheour at the University of Turku in Finland suspected that they might progress this fast because they learn language while they sleep as well as when they are awake: To test the theory, Cheour and their colleagues studied 45 newborn babies in the first days of their lives. They exposed all the infants to an hour of Finnish vowel sounds one that sounds like "oo", another like "ee" and a third boundary vowel peculiar to Finnish and similar languages that sounds like something in between. EEG(脑电图) recording of the infants brains before and after the session showed that the newborns could not distinguish the sounds. Fifteen of the babies then went back with their mothers, while the rest were split into two sleep-study groups. One group was exposed throughout their night-time sleeping hours to the same three vowels, while the others listened to the other, easier-to-distinguish vowel sounds. When tested in the morning, and again in the evening, the babies who'd heard the tricky boundary vowels all night showed' brainwave activity indicating that they could now recognize this sound. They could identify the sound even when its pitch was changed, while none of the other babies could pick up the boundary vowel at all. Cheour doesn't know how babies accomplish this nighttime learning, but she suspects that the special ability might indicate that unlike adults, babies don't "turn off" their cerebral cortex(大脑皮层)while they sleep. The skill probably fades in the' course of the first years of life, she adds—so forget the idea that you can pick up the tricky French vowels as an adult just by slipping a language tape under your pillow. But while it may not help grown-ups, Cheour is hoping to use the sleeping hours to give remedial help to babies who are genetically at risk of language disorders.

单选题The reason for their unusual behavior remains a puzzle.

单选题Don't hazard your reputation by supporting his joint venture with the gay from Los Angels.A. adventureB. riskC. threatenD. venture

单选题For most people the decision to wed is generally surrounded by social constraints.A. marryB. emigrateC. choose a jobD. have children

单选题About one million Americans are diagnosed，{{U}}annually{{/U}} with skin cancer

单选题The workers finally called off the strike.

单选题{{B}}第二篇{{/B}} {{B}} Electronic Mail{{/B}} During the past few years, scientist the world over have suddenly found themselves productively engaged in task they once spent their lives avoiding-writing, any kind of writing but particularly letter writing. Encouraged by electronic mail's surprisingly high speed, convenience and economy, people who never before touched the stuff are regularly, skillfully, even cheerfully tapping out a great deal of correspondence. Electronic networks, woven into the fabric of scientific communication these days, are the route to colleagues in distant counties, shared data, bulletin boards and electronic journals. Anyone with a personal computer, a modem and the software to link computers over telephone lines can sign on. An estimated five million scientists have done so with more joining every day, most of them communicating through a bundle of interconnected domestic and foreign routes known collectively as the internet, or net. E-mail is staring to edge out the fax, the telephone, overnight mail, and of course, land mail. It shrinks time and distance between scientific collaborators, in par[ because it is conveniently asynchronous (writers can type while their colleagues across time zones sleep; their message will be waiting). If it is not yet speeding discoveries, it is certainly accelerating communication. Jeremy Bernstei, the physicist and science writer, once called E-mail the physicist's umbilical cord. Lately other people, too, have been discovering its connective virtues. Physicists are using it; college students are using it, everybody is using it, and as a sign that it has come of age, the New Yorker has accelerates its liberating presence with a cartoon--an appreciative dog seated at a keyboard, saying happily, "On the Internet, nobody knows you're a dog."

单选题We have to put up with her behavior.

单选题The book took ten years of thorough research.A. basicB. carefulC. socialD. major

单选题Since the Great Depression, the United States government has protected farmers from (damaging) drops in grain prices.

单选题The secretary is expected to explore ideas for post-war reconstruction of the area.

单选题Helen will leave immediately .