填空题 阅读下面这篇短文，短文后有2项测试任务：(1)第23～26题要求从所给的6个选项中为第1～4段每段选择1个正确的小标题；(2)第27～30题要求从所给的6个选项中选择4个正确选项，分别完成每个句子。 {{B}}Cloning (克隆): Future Perfect?{{/B}}1 A clone is an exact copy of a plant or animal produced from any one cell. Since Scottish scientists reported that they had managed to clone a sheep named Dolly in 1997, research into cloning has grown rapidly. In May 1998, scientists in Massachusetts managed to create two identical calves (牛犊) using cloning technology. A mouse has also been cloned successfully. But the debate over cloning humans really started when. Chicago physicist Richard Seed made a surprising announcement: "We will have managed to clone a human being within the next two years," he told the world.2 Seed's announcement provoked a lot of media attention, most of it negative. In Europe, nineteen nations have already signed an agreement banning human cloning and in the US the President announced: "We will be introducing a law to ban all human cloning and many states in the US Will have passed anti-cloning laws by the end of the year."3 Many researchers are not so negative about cloning. They are worried that laws banning human cloning will threaten important research. In March, The New England Journal of Medicine called any plan to ban research on cloning humans seriously mistaken. Many researchers also believe that in spite of attempts to ban it, human cloning will have become routine by 2010 because it is impossible to stop the progress of science.4 Is there reason to fear that cloning will lead to a nightmare world? The public has been bombarded (轰炸) with newspaper articles, television shows and films, as well as cartoons. Such information is often misleading, and makes people wonder what on earth the scientists will be doing next.5 Within the next five to ten years scientists will probably have found a way of cloning humans. It could be that pretty soon we will be able to choose the person that we want our child to look like. But how would it feel to be a clone among hundreds, the anti-cloners ask. Pretty cool, answer the pro-cloners (赞成克隆的人).

补全短文Sleep Sleep is part of a persons daily activity cycle. There are several different stages of sleep, and they too occur in cycles._________(46). When you first drift off into slumber, your eyes will roll about a bit, your temperature will drop slightly, your muscles will relax, and your breathing will slow and become quite regular. Your brain waves slow down a bit too, with the alpha rhythm of rather fast waves predominating for first few minutes._________(47). For the next half hour or so, as you relax more and more, you will drift down through stage 2 and stage 3 sleep._________(48 ). Then, about 40 to 60 minutes after you lose consciousness, you will have reached the deepest sleep of all. Your brain waves will show the large slow waves that are known as the delta rhythm. This is stage 4 sleep. You do not remain at this deep fourth stage all night long._________(49). The delta rhythm will disappear, to be replaced by the activity pattern of brain waves. Your eyes will begin to dart around under your closed eyelids as if you were looking at something occurring in front of you. This period of rapid eye movement lasts for some 8 to 15 minutes and is called REM sleep._________(50). Provided that you do not wake up during the first REM sleep period, your body will soon relax again, your breathing will grow slow and regular once more, and you will slip gently back from stage 1 to stage 4 sleep—only to rise once again to the surface of near consciousness some 80 minutes later. A. But instead about 80 minutes after you fall into slumber, your brain activity level will increase again slightly. B. The lower your stage of sleep, the slower your brain waves will be. C. Your brain is still working when you are sleeping. D. If you are an average sleeper, your sleep cycle is as follows. E. It is during REM sleep that most dreams seem to occur. F. This is called stage 1 sleep.

补全短文The Function of Adrenocorticotriopin Some people can quite accurately time the end of their night''s sleep at will, without using an alarm clock, demonstrating that it is possible to voluntarily control a state of consciousness that is characterized by a loss of volition and attentional guidance. Here we show that the expectation that sleep will come to an end at a certain time induces a marked increase in the concentration of the hormone adrenocorticotriopin(促肾上腺皮质激素) in the blood one hour before waking. The regulation of adrenocorticotropin release during nocturnal sleep is therefore not confined to daily rhythms._________(46). _________(47). Normally, the release of adrenocorticotropin and cortisol(皮质醇) increases during late stages of sleeping, reaching a daily maximum at the time of spontaneous waking. Adrenocorticotropin and Cortisol are also released from the pituitary-adrenal system in a major adaptive response to stress, and are secreted in anticipation of stressful events. We investigated whether the increase in the secretion of pituitary-adrenal hormones during the late stages of sleeping in part reflects anticipation of the stress’ of the waking phase. _________( 48 ). We made recordings of electroencephalogram, electrooculogram and electromyogram throughout the night, and took blood samples every 15 minutes to determine plasma concentrations of adrenocorticortropin and Cortisol. Lights were turned off at midnight, after subjects had been told they would be woken at eight 6:00 ( ''short sleep’, on one night) or 9:00(''long sleep'', on the other two nights). On one of the long-sleep nights they were woken at 9:00 as they expected, but on the other night they were instead woken at 6:00 (''surprise'') under the pretence of a technical problem._________(49). We interviewed the volunteers at the end of the experiments, and found that all but one of the subjects had expected to be woken up at the specified time. The order of the three experimental nights was balanced across subjects, with five subjects starting with short sleep, five with long sleep, and five with the surprise condition. The increase in adrenocorticotropin release before the expected time of waking indicates that anticipation, which is generally considered to be unique characteristic of the regulation of conscious action, pervades sleep_________(50). The regulation of adrenocorticotropin release points to a mechanism that quickly adjusts endocrine activity to sharp changes in the duration. A. The regulation of sleep termination has been thought to be embedded in a daily rhythm controlling in paralleling the release of pituitary and adrenal hormones. B. Fifteen healthy volunteers with regular sleep-wake rhythms were studied during three nights. C. It also reflects a preparatory process in anticipation of the end of sleep. D. After being woken, subjects stayed in bed for another three hours. E. The anticipatory adrenocorticotropin increase may also facilitate spontaneous waking. F. About 10 million Americans consult doctors sleep problems each year.

补全短文Food And Cancer Medical experts have suspected for many years that there is a strong link between what a person eats and cancer._________(46). A team of Chinese and American scientists did the study. They are from American National Cancer Institute and the Cancer Institute of the Chinese Academy of Medical Sciences in Beijing. The Journal of the National Cancer Institute published the results of the study. About thirty thousand people between the ages of 40 to 69 took part in the study. They were from the northern central Chinese area of Linxian. Most of them took vitamins and minerals every day for five years. _________(47). Researchers believe that fungus and molds in local foods may be partly responsible for the high cancer rate. Researchers divided those into eight groups. Seven of the groups received different mixtures of vitamins and minerals daily. The amounts of the vitamins and minerals were 1 to 2 times greater than what American health officials say is needed._________(48). Those who seemed to gain the most received a mixture of a form of vitamin A called β-carotene, vitamin E and the mineral selenium. The vitamin and mineral are believed to prevent damage to cells caused by cancer-causing substances. Researchers reported a 13 percent drop in cancer rates in those who took β-carotene, vitamin E and selenium. They also found a 10 percent drop in the number of deaths caused by strokes from bursting blood vessels. _________(49 ). They note that the people in Linxian eat foods that lack necessary vitamins and minerals. Chinese officials will continue to record the health records of the people in Linxian for many years. For now officials reportedly are considering using the results of the study._________(50). A. The eighth group received sugar pills that had no effect. B. Fungus and molds in local food may be partly responsible for the high cancer rate in Linxian. C. Linxian was chosen because the people there have an extremely high rate of cancer of stomach and esophagus(食道). D. Scientists warn drat it is too soon to know if the effect would be the same among people in other counties. E. They say a new study provide the first evidence that vitamins could reduce a person''s chance of developing cancer. F. They want to find a way to improve the health of people in Linxian and other small towns in China.

补全短文Why do people shrinks Did you ever see the movie Honey, I shrunk the kids? It''s about a wacky dad (who''s also a scientist) who accidentally shrinks his kids with his homemade miniaturizing invention. Oops! (46)______ For older people, shrinking isn’t that dramatic or sudden at all. It takes place over years and may add up to only one inch or so off of their adult height ( maybe a little more, maybe less ) , and this kind of shrinking cant be magically reversed, although there are things that can be done to stop it or slow it down. (47)______ There are a few reasons. As people get older, they generally lose some muscle and fat from their bodies as part of the natural aging process. Gravity (the force that keeps your feet on the ground) take hold, and the bones in the spine, called vertebrae, may break down or degenerate, and start t? collapse into one another. (48)______ But perhaps the most common reason why some older people shrink is because of osteoporosis. Osteoporosis occurs when too much spongy bone tissue ( which is found inside of most bones) is broken down and not enough new bone material is made. (49)______ Bones become smaller and weaker and can easily break if someone with osteoporosis is injured. Older people—especially women, who generally have smaller and lighter bones to begin with—are more likely to develop osteoporosis. As years go by, a person with osteoporosis shrinks a little bit. Did you know that every day you do a shrinking act? You aren’t as tall at the end of the day as you are at the beginning. That''s because as the day goes on, water in the disks of the spine gets compressed (squeezed) due to gravity, making you just a tiny bit shorter. Don’t worry, though. (50)______ A. They end up pressing closer together, which makes a person lose a little height and become shorter. B. Once you get a good night''s rest, your body recovers, and the next morning, you''re standing tall again. C. Over time, bone is said to be lost because it''s not being replaced. D. Luckily, there are things that people can do to prevent shrinking. E. The kids spend the rest of the movie as tiny people who are barely visible while trying to get back to their normal size. F. But why does shrinking happen at all?

补全短文Broken: Dreams of Rural Peace It was dusk in Tubney Woods, deep in rural Oxfordshire. The birds were singing at the end of another perfect day. The woman living at the edge of the forest could stand it no longer. She phoned the local noise pollution officer. "It''s the rooks (秃鼻乌鸦)," she said. "I can''t bear that awful cawing (呱呱地叫) noise. Can you do something about it?" The call was no surprise to officials at the Vale of White Horse District Council. _________ (46). The countryside, as every country-dweller knows, can be a hellishly (可怕地) noisy place. Last week David Stead, a West Yorkshire farmer, appeared in court in Wakefield accused of allowing his cocks to break noise regulations by crowing (打鸣) at dawn, waking a neighbour. _________ (47). Six months ago Corky, a four-year-old cock, was banned from crowing after complaints in the Devon village of Stoke. Complaints about noise reasonable or not—are at record levels in country areas. Environmental health officers say this is partly because of an increase in noisy activity. However, a significant number of complaints come from newcomers to the countryside. There are many sources of rural noise._________ (48 ). Mechanised grain driers, usually switched on for three weeks in September, can produce a maddening low-frequency hum. Mike Roberts, chief environmental health officer at Vale of White Horse, said noise often sounded worse in the countryside than in cities. With less background sound, unwelcome noises can seem louder and travel further. The oddest complaints, however, are the ones council officials can do nothing about. Vale of White Horse officials have been asked to silence not only nesting rooks. Pigeons and pheasants (雉鸡) have also caused concern. In Kent, council officials have been asked to silence baby lambs. _________ (49) . Another insisted he could hear an alien spaceship landing over the garden fence. "We get regular complaints. They usually come from retired people who have just moved into the country. We send them a polite letter. " And the lady who complained about the rooks? She was politely told she would have to put up with it. "_________ (50)" said Mr. Roberts. "In the end, she accepted there .was nothing much she could do—except move out. " It is not recorded who won, the lady or the rooks. A. Mr. Stead said they were only doing what comes naturally. B. We asked her what we were supposed to do, shoot the birds, or chop the trees down? C. They have heard every kind of complaint. D. One man rang to say he was kept awake by the splashing of a fountain in the garden next door. E. The council will ask the fanner to move it. F. Farm machinery is a common cause.

补全短文A New Method to Kill AIDS Virus _________(46). But researchers won''t know for a year or more whether it will work, scientist David Ho told journalists here Wednesday for the Fourth Conference in Viruses and Infections. "This is a study that''s in progress," said Ho, head of the Aaron Diamond AIDS Research Center, New York. The study involves 20 people who started combinations of anti-HIV drugs very early in the course of the disease, within 90 days of their infections. They''ve been treated for up to 18 months. Four others have dropped out because of side effects or problems complying with the exacting drug system. The drugs have knocked the AIDS virus down to undetectable levels in the blood of all remaining patients. And, in the latest development, scientists have now tested lymph nodes (淋巴结) and semen (精液) from a few patients and found no virus reproducing there._________(47). Ho has calculated that the drugs should be able to wipe out remaining viruses—at least from known reservoirs throughout the body—in two to three years._________(48). Oh Wednesday, Ho said he wouldn’t ask any patient to consider that step before 2.5 years of treatment. And he emphasized that he is not urging widespread adoption of such early, aggressive treatment outside of trials._________(49). _________(50). A federally funded study will put 300 patients on triple-drug treatments and then see if some responding well after six months can continue to suppress the virus on just one or two drugs, says researcher Douglas Richman of the University of California, San Diego. Some patients in that study also may be offered the chance to stop therapy after 18 months or more, he says. A. The attempt to eradicate the AIDS virus continues to be hopeful. B. But the only way to prove eradication would be to stop the drugs and see if the virus comes back. C. But other scientists are looking at similar experiments. D. Bear in mind that undetectable does not equal absent, Ho says. E. No one knows the long-term risks. F. A high-profile attempt to eradicate the AIDS virus in a few patients continues to show promise.