单选题They agreed to {{U}}modify{{/U}} their policy. A. clarify B. change C. define D. develop

单选题1. Mental Retardation Mental retardation is a condition in which people have lower than normal intelligence and are unable to function at the level expected for their age. People with mental retardation are usually born with it, or it develops early in their life. They may also have some difficulty with dally living skills such as learning to read and write and caring for themselves. Doctors and other professionals determine that a person has mental retardation based on their intelligence and how well they can do everyday activities. Intelligence is the ability to learn and understand. Levels of intelligence are measured by special tests called intelligence tests. The score a person gets on one of these tests gives a numerical measure of a person' s intelligence. This is called an intelligence quotient or IQ. An average score on an IQ test is about 90 to 110. A person with mental retardation will usually score below 75 on an IQ test. The IQ test alone does not determine whether someone is mentally retarded. A person must also have trouble with everyday activities such as getting dressed, eating, or washing or learning basic reading, writing, and arithmetic skills. Mental retardation is not a disease itself. It cannot be cured and it's not contagious (传染的). This condition can be caused by several things that injure the brain or don ' t allow the brain to develop normally. Many times we don' t know why a person has mental retardation. Sometimes it may be caused by genes. Genes are chemical units found in every cell. They carry the instructions telling cells what to do. Sometimes, children receive abnormal genes from their parents. A defective gene may also develop spontaneously. Neither parent would have passed on the gene, but the gene changes before the baby develops. Some other problems that can cause mental retardation also happen before a child is born. It is important: for the brain to develop properly if a child is to have normal intelligence. " Planning a pregnancy is the most important decision most of us will make in our lifetime. A healthy lifestyleand good medical care should begin before a woman becomes pregnant and continue throughout the pregnancy, "says Jodi Rucquoi, a genetic counselor from Connecticut. If a woman abuses alcohol or drugs or doesn' t eat well, there is a risk to the developing baby. Also, a premature birth or problems during childbirth can sometimes harm the baby "s developing brain. While premature babies are generally fine, there is a greater chance that they may have mental retardation. In some cases, a young child can develop mental retardation after being sick with a serious infection or other illness, or after suffering a bad head injury.

单选题Quite a few New Yorkers took their mayor's recent advice and got a flu shot.

单选题They tried their best to resolve the residual problems.A. domesticB. remainingC. geographicalD. elaborate

单选题Stone Hill Mall is popular with shoppers mainly because of its

单选题The next morning she told us that the last guests didn't Udepart/U till well after midnight.

单选题Before the invention of photoengraving,steel and copperplate engraving served as the principal means of reproducing illustrations.

单选题Pure feldspar is a colorless, transparent mineral, but impurities {{U}}commonly{{/U}} make it opaque and colorful. A. truly B. rapidly C. periodically D. frequently

单选题 Pool Watch Swimmers can drown in busy swimming pools when lifeguards fail to notice that they are in trouble. The Royal Society for the Prevention of Accidents says that on average 15 people drown in British pools each year, but many more suffer major injury after getting into difficulties. Now a French company has developed an artificial intelligence system called Poseidon that sounds the alarm when it sees someone in danger of drowning. When a swimmer sinks towards the bottom of the pool, the new system sends an alarm signal to a poolside monitoring station and a lifeguard's pager. In trials at a pool in Ancenis, near Nantes, it saved a life within just a few months, says Alistair McQuade, a spokesman for its maker, Poseidon Technologies. Poseidon keeps watching through a network of underwater and overheard video cameras. AI software analyses the images to work out swimmers' trajectories. To do this reliably, it has to tell the difference between a swimmer and the shadow of someone being cast onto the bottom or side of the pool. "The underwater environment is a very dynamic one, with many shadows and reflections dancing around," says McQuade. The software does this by "projecting" a shape in its field of view onto an image of the far wall of the pool. It does the same with an image from another camera viewing the shape from a different angle. If the two projections are in the same position, the shape is identified as a shadow and is ignored. But if they are different, the shape is a swimmer and so the system follows its trajectory. To pick out potential drowning victims, anyone in the water who starts to descend slowly is added to the software's "pre-alert" list, says McQuade. Swimmers who then stay immobile on the pool bottom for 5 seconds or more are considered in danger of drowning. Poseidon double-checks that the image really is of a swimmer, not a shadow, by seeing whether it obscures the pool's floor texture when viewed from overhead. If so, it alerts the lifeguard, showing the swimmer's location on a poolside screen. The first full-scale Poseidon system will be officially opened next week at a pool in High Wycombe, Buckinghamshire. One man who is impressed with the idea is Travor Baytis, inventor of the clockwork radio. Baylis runs a company that installs swimming pools, and he was once an underwater escapologist with a circus. "I say full marks to them if this works and can save lives," he says. But he adds that any local authority spending ￡30,000 plus on a Poseidon system ought to be investing similar amounts in teaching children to swim.

单选题Thousands of people perished in the storm.

单选题Common-cold Sense You can't beat it, but you don't have to join it. Maybe it got the name "common cold" because it's more common in winter. The fact is, though, being cold doesn't have anything to do with getting one. Colds are caused by the spread of rhinoviruses, and. at least so far, medical science is better at telling you how to avoid getting one than how to get rid of one. Children are the most common way cold viruses are spread to adults, because they have more colds than adults an average of about eight per year. Why do kids seem so much more easily to get colds than their parents? Simple. They haven't had the opportunity to become immune to many cold viruses. There are more than 150 different cold viruses, and you never have the same one twice. Being infected by one makes you immune to it — but only it. Colds are usually spread by direct contact, not sneezing or coughing. From another person's hand to your hand and then to your nose or eyes is the most common route. The highest concentration o cold viruses anywhere is found under the thumbnails of a boy, although the viruses can survive for hours on skin or other smooth surfaces. Hygiene is your best defense. Wash your hands frequently, preferably with a disinfectant soap, especially when children in your household have colds. But even careful hygiene won't ward off every cold. So, what works when a coughing, sneezing, runny nose strikes? The old prescription of two aspirins, lots of water, and bed rest is a good place to start. But you'll also find some of the folk remedies worth trying. Hot mixtures of sugar (or honey), lemon, and water have real benefits.

单选题 In the recent past, medical researchers have shown that heart disease is associated with certain factors in our day-to-day lives: with stress, with smoking, with poor nutrition (营养), and with a {{U}}(51) {{/U}} of exercise. Doctors and other health experts have been {{U}}(52) {{/U}} the fact that we can often reduce the {{U}}(53) {{/U}} of heart disease by paying more attention to these factors. More and more people are realizing that there is a {{U}}(54) {{/U}} between heart disease and the way they live. As a result of this new {{U}}(55) {{/U}}, attitudes toward health are changing:In the past, people tend to think that it was sufficient for good health to have a good doctor who could be {{U}}(56) {{/U}} on to know exactly what to do when they became ill. {{U}}(57) {{/U}} they are realizing that merely receiving the best treatment {{U}}(58) {{/U}} illness or injury "is not enough. They are learning that they must {{U}}(59) {{/U}} more responsibility for their own health. Today many people are changing their dietary {{U}}(60) {{/U}} and eating food with less fat and cholesterol(胆固醇). Many are paying more attention to reducing {{U}}(61) {{/U}} in their lives. The number of smokers in the United States is now far below the level of twenty years ago because many people succeed in breaking the habit and as fewer people {{U}}(62) {{/U}} it up. More and more are aware of the {{U}}(63) {{/U}} of regular exercise like walking, running, or swimming, some have begun to walk or ride bicycles to work instead of made. Millions have become members of health clubs and have made health clubs one of the fastest growing businesses in the United States today. And now the {{U}}(64) {{/U}} effects of these changing attitudes and behaviors are beginning to appear: a(n) {{U}}(65) {{/U}} decrease in deaths from heart disease.

单选题How often should the employees exercise to help lower the health-care costs?

单选题In the old days, children were familiar with birth and death as part of life. This is perhaps the first generation of American youngster(年轻人)who have never been close by during the birth of a baby and have never experienced the death of a family member. Nowadays when people grow old, we often send them to nursing homes. When they get sick, we transfer them to a hospital, where children are forbidden to visit terminally ill patients--even when those patients are their parents. This deprives(剥夺)the dying patient of significant family members during the last few days of his life and it deprives the children of an experience of death, which is an important learning experience. Some of my colleagues and I once interviewed and followed approximately 500 terminally ill patients in order to find out what they could teach us and how we could be of more benefit, not just to them but to the members of their families as well. We were most impressed by the fact that even those patients who were not told of their serious illness were quite aware of its potential outcome. It is important for family members, and doctors and nurses to understand these patients' communications in order to truly understand their needs, fears, and fantasies(幻想). Most of our patients welcomed another human being with whom they could talk openly, honestly, and frankly about their trouble. Many of them shared with us their tremendous need to be informed, to be kept up-to-date on their medical condition, and to be told when the end was near. We found out that patients who had been dealt with openly and frankly were better able to cope with the approach of death and finally to reach a true stage of acceptance prior to death.

单选题Cattle graze on the dry uplands of the island of Hawaii.A. wanderB. breedC. feedD. exercise

单选题{{B}}第三篇{{/B}} For years doctors have given cancer patients three main treatments: surgery, radiation and chemotheraphy. Now researchers are developing a fourth weapon: the patient' s own immune system. New vaccines(疫苗)and drugs can stimulate the production of an army of cells and antibodies that kill cancer cells. Drug-vaccine therapy may be lifesaver for Deerfield man. Few people survive advanced melanoma, but immune therapy is giving Deerfield resident Douglas Parker a fighting chance. The 46-year-old salesman noticed a mole on his chest three and a half years ago that was found to be cancerous. Doctors removed the mole but didn't get all of the cancer. The cancer spread to other parts of his body, including his liver, where a tumor grew as large as a baseball. Parker took interferon and interleukin-2 to boost his immune system's ability to fight the cancer. The tumor shrank but didn't disappear. In au- gust, 1997, surgeons removed it, along with two-thirds of his liver. Last January, doctors discovered a new tumor on Parker's left adrenal gland(肾上腺). He received an ex- perimenta1 cancer vaccine at the University of Chicago Hospitals, but the vaccine did n' t stop the cancer from spreading to his right adrenal gland. To augment the vaccine, doctors at Lutheran General Hospital gave Parker a new round of interleukin-2 and interferon. The drug-vaccine combination has shrunk the tumors. And while it's too early to pronounce Parker cured, immune therapy may save his life. "I want to do this to help myself as well as other people who have melanoma," he said. Immune therapy "ultimately will be a significant change in the way we treat a lot of different cancers," said Dr. Jon Richards of Lutheran General Hospital in Park Ridge, who is testing cancer vaccine on melanoma patients. "It will be an equal partner with the other three treatments in the next five to ten years." Several drugs that bolster the immune system have been approved, and vaccines are being tested in dozens of clinical trials, including several in the Chicago area. Many of the experimental vaccines have been tested on patients with advanced melanoma who have little chance of surviving with conventional treatments alone. Researchers also have begun doing work that could lead to vaccines to treat prostate, lung, colon and other cancers. Immune therapy alone won't cure cancer. But when used after conventional treatments, it could kill cancer cells that survive surgery, radiation or chemotherapy, re- searchers said. Some day, vaccines also might be able to prevent certain cancers. It may be possible to vaccinate against viruses and bacteria that help cause cervical, liver and stomach cancer, the National cancer Institute said.

单选题Preferences Vary on Circumstances of Dying Among terminally (晚期) ill people, attitudes differ on what they think constitutes a 1 or bad death, the results of a new study suggest. Dr. Elizabeth K. Vig of the University of Washington in Seattle and colleagues interviewed 26 men with 2 heart disease or cancer. The men were asked to describe good and bad deaths, and they also answered 3 about their preferences for dying. "In this small study, terminally ill men described good and bad deaths 4 ," Vig said. "They did not hold the same views about such issues 5 the presence of others at the very end of life or preferred location of death." Many of the men considered 6 in their sleep to be a good death. The reasons were varied and included not 7 that death was imminent (即将发生的), and that death would be painless. For close to half of the men, a prolonged (拖延的) death was 8 a bad death. Some of the men associated a prolonged death with prolonged pain, 9 others thought a prolonged death would be difficult for their families. Most men said that their 10 were very important to them, but this did not mean that they wanted relatives close at the 11 of death. "Valuing family did not also 12 wanting family present at the very end of life," Vig said. "In fact, some expressed concerns 13 burdening loved ones," Vig said. For instance, some men were worried about the emotional or 14 impact on their family members, according to the Washington researcher. Some were worried 15 their need for care would be a burden on their families, she said.

单选题Even in a highly modernized country, manual work is still needed. A. physical B. mental C. natural D. hard

单选题A Gay Biologist Molecular biologist Dean Hamer has blue eyes, light brown hair and a good sense of humor. He smokes cigarettes, spends long hours in an old laboratory at the US National Institute of Health, and in his free time climbs up cliffs and points his skis down steep slopes. He also happens to be openly, matter-of-factly gay. What is it that makes Hamer who he is? What, for that matter, accounts for the talents and traits that make up anyone's personality? Hamer is not content merely to ask such questions; he is trying to answer them as well. A pioneer in the field of molecular psychology, Hamer is exploring the role genes play in governing the very core of our individuality. To a remarkable extent. his work on what might be called the gay, thrill-seeking and quit-smoking genes reflects how own genetic predispositions. That work, which has appeared mostly in scientific journals, has been gathered into an accessible and quite readable form in Hamer's creative new book, Living with Our Genes. "You have about as much choice in some aspect of your personality, " Hamer and co-author Peter Copeland write in the introductory chapter, "as you do in the shape of your nose or the size of your feet. " Until recently, research into behavioral genetics was dominated by psychiatrists and psychologists, who based their most compelling conclusions about the importance of genes on studies of identical twins. For example, psychologist Michael Bailey of Northwestern University famously demonstrated that if one identical twin is gay, there is about a 50% likelihood that the other will be too. Seven years ago, Hamer picked up where the twin studies left off, homing in on specific strips of DNA that appear to influence everything from mood to sexual orientation. Hamer switched to behavioral genetics from basic research; after receiving his doctorate from Harvard, he spent more than a decade studying the biochemistry of a protein that cells use to metabolize heavy metals like copper and zinc. As he was about to turn 40, however, Hamer suddenly realized he had learned as much about the protein as he cared to. "Frankly, I was bored, " he remembers, "and ready for something new. " Homosexual behavior, in particular, seemed ripe for exploration because few scientists had dared tackle such an emotionally and politically charged subject. "I'm gay, " Hamer says with a shrug, "but that was not a major motivation. It was more of a question of intellectual curiosity — and the fact that no one else was doing this sort of research. /

单选题Exercise Cuts Cancer Deaths in Men Men who exercise often are less likely to die from cancer than those who (51) , new research published in the British Journal of Cancer revealed yesterday. A team of scientists from the Karolinska Institute in Sweden looked (52) the effect of physical activity and cancer risk in 40,708 men (53) between 45 and 79. The seven-year study found that men (54) walked or cycled for at least 80 minutes a day had a 84 percent lower risk of (55) from cancer than the men who did less exercise or nothing at all. (56) the period studied, 3,714 men developed cancer and 1,153 died from the disease. The researchers suggest that half an hour's walking (57) 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 (58) activity they were usually doing. They then scored these responses and compared the results (59) data on cancer diagnosis and death officially recorded in a central cancer registry 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 (60) such as walking or cycling has in reducing cancer death risk in middle-aged and elderly (61) " 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 (62) to die from cancer, and that they are more likely to (63) the disease if they get it. It's not entirely clear from this study what role exercise plays in preventing (64) in men, but we do know that a healthy lifestyle can prevent up to half of all cancers and (65) exercise forms a key part of this. /