单选题The commercial telephone service was no longer {{U}}operative{{/U}}. A. creative B. moving C. rotating D. working

单选题Sleep Lets Brain File Memories To sleep. Perchance to file? Findings published online this week by the Proceedings of the National Academy of Sciences further support the theory that the brain organizes and stows memories formed during the day while the rest of the body is catching zzz"s. Gyorgy Buzsaki of Rutgers University and his colleagues analyzed the brain waves of sleeping rats and mice. Specifically, they examined the electrical activity emanating from the somatosensory neocortex (an area that processes sensory information) and the hippocampus, which is a center for learning and memory. The scientists found that oscillations in brain waves from the two regions appear to be intertwined. So-called sleep spindles (bursts of activity from the neocortex) were followed tens of milliseconds later by beats in the hippocampus known as ripples. The team posits that this interplay between the two brain regions is a key step in memory consolidation. A second study, also published online this week by the Proceedings of the National Academy of Sciences, links age-associated memory decline to high glucose levels. Previous research had shown that individuals with diabetes suffer from increased memory problems. In the new work, Antonio Convit of New York University School of Medicine and his collaborators studied 30 people whose average age was 69 to investigate whether sugar levels, which tend to increase with age, affect memory in healthy people as well. The scientists administered recall tests, brain scans and glucose tolerance tests, which measure how quickly sugar is absorbed from the blood by the body"s tissues. Subjects with the poorest memory recollection, the team discovered, also displayed the poorest glucose tolerance. In addition, their brain scans showed more hippocampus shrinkage than those of subjects better able to absorb blood sugar. "Our study suggests that this impairment may contribute to the memory deficits that occur as people age." Convit says. "And it raises the intriguing possibility that improving glucose tolerance could reverse some age-associated problems in cognition." Exercise and weight control can help keep glucose levels in check, so there may be one more reason to go to the gym.

单选题You have to be patient if you want to sustain your position.

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。 There is no doubt that we are living in a period of enormous population growth. In the past, it{{U}} (51) {{/U}}thousands of years for the world's population to double in size.{{U}} (52) {{/U}}today there are more people having families and fewer deaths from diseases. As(a){{U}} (53) {{/U}}, the population doubles in only 35 years. A(n){{U}} (54) {{/U}}supply of food is only one of the human needs that must be{{U}} (55) {{/U}}. Overcrowding has a highly undesirable effect on life. For example, if every available piece of land were used for producing food, it would be very difficult to{{U}} (56) {{/U}}proper housing for people, as would health care and recreation.{{U}} (57) {{/U}}these reasons, more governments are helping families to understand the problems of{{U}} (58) {{/U}}population. They give 'family planning' advice to families that request it. Such families can plan to have the number of children they want, at times when they are best able to care{{U}} (59) {{/U}}children and give them a good start in life.{{U}}(60) {{/U}}rice that have been highly successful in Asia and in{{U}} (61) {{/U}}African countries. The significance of such work was recognized by the awarding of the 1970 Nobel Peace Prize{{U}} (62) {{/U}}one of the plant breeders of the 'green revolution'.{{U}} (63) {{/U}}to grow well, the improved seeds need large{{U}} (64) {{/U}}of fertilizer and water, which are not always {{U}}(65) {{/U}}. Many fertilizers are made up of petroleum, and higher prices for oil have resulted in smaller supplies of fertilizers.

单选题She could not answer, it was an immense load off her heart.A. naturalB. fatalC. tinyD. enormous

单选题 阅读下面这篇短文，短文后列出了7个句子，请根据短文的内容对每个句子作出判断。如果该句提供的是正确信息，请选择A项；如果该句提供的错误信息，请选择B项：如果该句的信息文章中没有提及，请选择C项。 {{B}}Spare a Kidney?{{/B}} It is no longer unusual for a spouse or relative to donate a kidney to a loved one, but the number of Americans who have given a kidney to a friend, a co-worker or even a complete stranger has risen sharply from 68 in 1994 to 176 in 1998. There are many reasons. First, it's possible to live a normal life with only one kidney. (The remaining kidney enlarges to make up most of the difference.) In addition a kidney from a live donor lasts longer than a kidney taken from someone who has died suddenly. But the biggest change in the past few years is that transplant surgeons have started using laparoscopic techniques to remove the donor kidney through a much smaller incision, and this can cut recovery time for the donor from six weeks to four weeks. Just because you do something, however, it doesn't mean you should. Donating a kidney means undergoing an operation that carries some risk. You could argue that you may be helping to save a life, but you certainly can't pretend that you're better off with one kidney instead of two. So, what are the risks? "As with any major operation, there is a chance of dying, of reoperation due to bleeding, of infection, of vein clots in the legs or a hernia at the incision," says Dr. Arthur Matas, director of the renal-transplant program at the university of Minnesota Medical Center in Minneapolis. Even laparoscopy, a relatively new technique for kidney donation, is not risk-free. Doctors estimate that chances of dying from the procedure are about 3 in 10,000. There's no money to be made; selling an organ is illegal. But the recipient's insurance normally covers your operation and immediate aftercare. Your costs can include hotel bills, lost pay during recovery or possible future disability. Although transplant centers must evaluate any potential donor's suitability, it never hurts to have an independent opinion. The most common contraindications are heart disease, diabetes and high blood pressure. Never let anyone, not even a close relative, pressure you into giving up an organ--no matter if you're healthy. "There's often the feeling that you're not a good friend, father, mother if you don't do this," says Arthus Caplan, director of the University of Pennsylvania's center for Bioethics. Some transplant centers will invent a "medical problem" on behalf of those who are reluctant to donate but feel they can't say no.

单选题The room is dim and quiet.

单选题AIDS Eight to ten million people around the world are now infected with the virus that causes AIDS, and the incidence of the infection is rising dramatically in some parts of the world, the World Health Organization reports. The estimate is 1 with an earlier projection by the organization that 15 million to 20 million people would be infected by HIV by the year 2005. The 2 reflect the growing 3 of the AIDS virus around the world. "It is clear that the problem of HIV infection around the globe is 4 rapidly, especially in 5 countries in Africa and Asia," said Dr. Michael Merson, the director of the agency"s worldwide programs on AIDS. The new estimates are based on a recently 6 analysis of blood tests in which the AIDS virus was found in 1988 and 1989. The analysis showed that the 7 of HIV infection is slowing in industrialized countries. But in sub-Saharan African, cases of HIV infection have increased 8 about 5 million from 2.5 million in 1987. That year, most infected people were found in big cities; now the virus is spreading to 9 areas. The agency calculated that about one 10 40 adult men and women is infected in that region. 11 from Southern Asia, including Thailand and India, showed marked increase in HIV infection among female prostitutes (妓女) and people who inject drugs into themselves. The 12 number of HIV infection in Asia has risen from next to nothing two years ago to at least 500,000, the agency reported. The agency also 13 a rising incidence of HIV infection, AIDS cases and 14 among women and children in the 1990s, with three million of them 15 to die in the next decade.

单选题Not everyone is a good candidate for liposuction.

单选题The article {{U}}sketched{{/U}} the major events of the decade.

单选题The purpose of the $15 million program is to

单选题The bridge had been {{U}}wrecked{{/U}} by the explosion. A. shaken B. fallen C. damaged D. trembled

单选题{{B}}第一篇{{/B}} Social anxiety disorder prevents some 15 million Americans from leading normal social and romantic lives, a new survey finds. The disorder leaves many isolated, ashamed and often misdiagnosed. Thirty-six percent of those with social anxiety disorder have symptoms for 10 years or more before seeking help, the Anxiety Disorders Association of America reports. "Social anxiety disorder is when somebody has an intense, persistent and irrational fear of social or performance situations, " Jerilyn Ross, the association's president and CEO, said during a teleconference Wednesday. "The condition causes people to avoid common, everyday situations and even other people for fear of being judged or criticized or humiliated or embarrassing themselves, " Ross said. Social anxiety disorder can interfere with daily routines and job performance, Ross noted. "It also makes it very difficult for people to develop friends and romantic partnerships," she said. People with this disorder recognize their fear is excessive and irrational, Ross noted. "But they feel powerless to do anything about it," she said. Social anxiety disorder can start in the early teens, Dr. Mark H. Pollack, director of the Center for Anxiety and Traumatic Stress Disorders and a professor of psychiatry at Harvard Medical School, said during the teleconference. "This is a disorder that starts affecting people early on, " Pollack said. "The typical age of onset is early adolescence, age 12 or 13, and many individuals report a history of anxiety dating back to earlier childhood." The disorder also has physical symptoms, including heart palpitations, feelings that their throat will close up, sweating, blushing, faintness, trembling and stammering, Ross said. Among people with the disorder, 75 percent said the condition affected their ability to do normal activities. In addition, 69 percent said they didn't want people to think they were crazy, and 58 percent said they were embarrassed by their condition, Ross said. However, when the condition is diagnosed and treated, many reported improvement in their lives. In fact, 59 percent who were receiving treatment said treatment had a positive effect on their ability to have a romantic relationship. In addition, 39 percent who had received treatment said knowing that treatment can be successful aided their decision to get help, Ross noted.

单选题The little boy was sad because he had made a big mistake.A. largeB. seriousC. goodD. bad

单选题We had a long conversation about her parents. A. talk B. speech C. debate D. discussion

单选题I seldom watch TV.

单选题Relief workers were shocked by what they saw.

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。 As people continue to grow and age, our body systems continue to change. At a certain point in your life your body systems will begin to weaken. Your joints may become stiff. It may become more difficult for you to see and hear. The slow change of ageing causes our bodies to lose some of their ability to bounce back form disease and injury. In order to live longer, we have always tried to slow or stop this process that leads us toward the end of our lives. Many factors contribute to your health. A well-balanced diet plays an important role. The amount and type of exercise you get is another factor. Your living environment and the amount of stress you are under is yet another. But scientists studying senescence (衰老)want to know: Why do people grow old? They hope that by examining the ageing process on a cellular level medical science may be able to extend the length of life. There is nothing to be afraid of as old age approaches. Many consider the later portions of life to be the best time for living. Physical activity may lessen, but often you gain a broader understanding of yourself and the world. What we consider old age now may only be middle-aged some day soon. Who knows, with so many advances in medical science happening so quickly, life spans may one day be measured in centuries, rather than in years!

单选题Did anyone call me when I was out?

单选题The fighter plane fell into a mountain after take-off, its bombs exploding as it hit the ground.A. smashedB. castC. plungedD. crashed