单选题{{B}}第三篇{{/B}} {{B}} Late-night Drinking{{/B}} Coffee lovers beware. Having a quick "pick-me-up" cup of coffee late in the day will play havoc with you sleep. As well as being a stimulant, caffeine interrupts the flow of melatonin, the brain hormone that send people into a sleep. Melatonin levels normally start to rise about two hours before bedtime. Levels then peak between 2 a.m. and 4 a.m., before falling again. "It's the neurohormone that controls our sleep and tells our body when to sleep and when to wake," says Manrice Ohayon of the Stanford Sleep Epidemiklogy Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body's levels of this sleep hormone. Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six volunteers slept less well after a cup of caffeinated coffee than after drinking the same amount of decaf. On average, subjects slept 336 minutes per night after drinking caffeinated coffee, compared with 415 minutes after decaf. They also took half an hour to drop off--twice as long as usual-- and jigged around in twice as much. In the second phase of the experiment, the researchers woke the volunteers every three hours and asked them to give a urine sample. Shilo measured concentrations of a breakers were half those in decaf drinkers. The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers. In a paper accepted for publication in Sleep Medicine, the researchers suggest that caffeine blocks production of the enzyme the drives melatonin production. Because it can take many hours to eliminate caffeine from the body, Ohayon recommends that coffee lovers switch to decal after lunch.

单选题People of Burlington are being disturbed by the sound of bells. Four students from Burlington College of Higher Education are in the bell tower of the (51) and have made up their minds to (52) the bells nonstop for two weeks as a protest against heavy trucks which run (53) through thenarrow High Street. "They not only make it (54) to sleep at night, but they are (55) damage to our houses and shops of historical (56) , "said John Norris, one of the protesters. " (57) we must have these noisy trucks on the roads," said Jean Lacey, a biology student. "why don' t they build a new road that goes round the town? Burlington isn' t much more than a (58) village. Its streets were never (59) for heavy traffic. " Harry Fields also studying (60) said they wanted to make as much (61) possible to force the govemment officials to realize what everybody was having to (62) . "Most of them don' t (63) here anyway, "he said," they come in for meetings and that, and the Town Hall is soundproof, so they probably don' t (64) . It' s high time they realized the problem. "The fourth student, Liza Vemum, said she thought the public were (65) on their side, and even if they weren't they soon would be.

单选题Her novel depicts an ambitious Chinese.

单选题The research team needs to confer with the director before it begins its final report.

单选题Ohayon advises coffee lovers

单选题The vaccine may be useful for treating other cancers.

单选题Cosmetic Surgery Surgery that can improve the way a person looks is becoming more and more popular in the United States. This kind of surgery is called cosmetic surgery, and both men and women are turning to this treatment as a way of keeping their appearance young as well as keeping competitive (有竞争力的 ) in their jobs. Men especially are beginning to turn to face-lifts (面部拉皮手术), liposuction (taking fat out of the body), and implants (putting artificial parts into their bodies ) to help them look younger. As companies downsize (缩编) and move younger employees into higher positions, older employees in their late forties and early fifties feel the need to look and act younger in order to stay competitive. These operations are not without dangers, however. One young woman had an eye operation to get rid of the bags under her eyes. She described her experience as terrible. She said, "When he started cutting, I was fully awake. Even though he"d given me an injection near my eyes, I saw everything. " She went on to explain, "I knew I had to keep still because of what he was doing. He was scraping (刮) away fat underneath my eyes. It took about ten minutes. After he finished, I felt I couldn"t walk. I was so faint." Her troubles did not end after the operation for two weeks. Her eyes were swollen (肿胀的) and almost completely closed, and even dark glasses could not hide the side effects of the operation. Liposuction, taking fat out of the body, is probably the most popular cosmetic operation in the United States. It seems simple enough. First, a small cut is made over the place where the patient wants the fat removed. Next, a small pipe is put into the cut. A machine like a vacuum cleaner is then used to suck the fat out of the body. However, as one doctor explained, some problems can happen after the operation. He warned, "Irregular lumps and loose skin can reset from this operation. If it is not evenly done, liposuction can produce a very lumpy result." Patients often must have more liposuction to correct the problem.

单选题A ballet is theatrical entertainment that combines the arts of dancing, stage design, and music.

单选题The use of chemical may present a certain hazard to the laboratory workers.

单选题Please ensure that your seatbelts are fastened while driving.A. make outB. make forC. make upD. make sure

单选题Cement was seldom used in buildings of the Middle Ages.

单选题Medical bills in the United States have risen violently since 1960's and steps need to be taken to reverse this trend or the average American will not be able to afford medical care. The major factor in increasing the cost of medical care has been the dramatic increase in the cost of hospital services. The rise in the cost of hospitalization can be only partly blamed on inflation (通货膨胀)since hospital bills in the last two decades have risen at a considerably higher rate than inflation. Another factor cited by doctors as a major cause for the increase in the cost of medical care is malpractice(治疗错误). Increasingly large awards for malpractice have caused doctors to increase their rates to cover the higher malpractice insurance. Because of the large malpractice awards, doctors are also prescribing more conservative and more extensive and therefore more costly treatment for patients as a defense against malpractice claims. Whatever the causes of the wild increases in the cost of medical care are, the government needs to take strong action before it is too late for Americans.

单选题The reason why he adapted to the new situations quickly is that he has a flexible attitude.

单选题In judging our work you should take into Uconsideration/U the fact that we have been very busy recently.

单选题We explored the possibility of expansion at the conference.

单选题The girl is gazing at herself in the mirror.

单选题Fahrenheit and Celsius Daniel Gabriel Fahrenheit and Anders Celsius both began work on their respective temperature scales in the 18 th century. A Dutch instrument maker, Fahrenheit (1688—1736) built on the work of Danish astronomer Ole Romer, who spent considerable time making meteorological observations and experimenting with thermometers. During the late 1600s and early 1700s, Isaac Newton led the fields in experimenting with thermometry. According to Newton, 12 degrees should separate the temperature of a water, ice, and salt solution from the temperature of the human body. Fahrenheit believed that the thermometer he invented in 1714 had eight times the accuracy of Newton"s thermometer, and therefore 96 degrees should separate these benchmarks (eight times Newton"s range). Using this new scale, a combination of water, ice and salt solution stayed at 0°, and body temperature registered as 96°. With these marks intact, a combination of water and ice (the freezing point)equated 32°. Scientists later found that water boiled at 212° according to the Fahrenheit scale. After more accurate testing 95.6° became the corrected body temperature that we know today. Celsius (1701—1744), a Swedish astronomer, developed the centigrade scale a bit later in 1742. He assigned 100° to the freezing point and 0° to the boiling point. This scale appeared in Sweden and France, but with the numbers reversed. The Celsius system received broad recognition for his work in 1948 when his name became the official title of this temperature scale. Opinion is still divided as to why one scale found favour in some parts of the world while the other was widely accepted elsewhere. Daniel Kelves, a historian, offers this theory: "Part of the reason, "he says, "is that the Fahrenheit system was developed first, and by a Dutchman; Holland and England enjoyed friendly relations at the time. The system later travelled to the American colonies. After the invention of the Celsius system, the French under Napoleon were at loggerheads with England, probably enforcing the division as well, "he says. To convert degrees Fahrenheit to degrees Celsius, subtract 32, then multiply the result by five-ninths. To convert from Celsius to Fahrenheit, multiply by nine-fifths, then add 32.

单选题Launched in the autumn of 1976 in London, and now published ten times a year.A. EndedB. FollowedC. IncludedD. Started

单选题下面有3篇短文后有5道题。请根据短文内容，为每题定为1个最佳选项。{{B}}第一篇{{/B}} Dreams Studies show that in dreams things are seen and heard rather that thought. In terms of the senses, visual experience is present in almost all dreams; auditory experience in 40 to 50 percent; and touch, taste, smell, and pain in a relatively small percentage. A considerable amount of emotion is commonly present, usually a pure and single emotion such as fear, anger, or joy. The clearly distinguishable states of sheep exist. The first state, called NREM-sheep (non-rap-id-eye movement sleep), occupies most of the sleep period and is associated with a relatively low pulse and blood pressure, and few or no reports of dreaming. The second type of sheep, known as REM-sleep (rapid-eye-movement sleep) occurs cyclically during the sleep period with rapid eye movements and frequent dream reports. Typically, a person has four or five periods of REM-sleep during the night, whether the dreams are remembered often, rarely, or not at all; they occur at intervals of about 90 minutes and altogether make up about 25 percent of the night's sleep (as much as 50 percent in a newborn child). Evidence indicates that a dream period usually lasts from 5 to 20 minutes. Sounds and touches working on a dreamer can go into a dream if they occur during a Remperiod. Although mental activity may be reported during NREM-sleep, these are usually short pieces of thought like experiences. Modern dream research has focused on two general interpretations of dream content. In one view, dreams have no meaning of their own but are simply a process by which the brain integrates new information into memories. In the other view, dreams contain real meaning symbolized in a picture language distinct from conscious logical thought. If dreams express important wishes, fears, concerns, and worries of the dreamer, the study and analysis of dreams can help reveal previously unknown aspects of a person's mental functioning.

单选题The leaves of the eucalyptus tree can be used to make a potent antiseptic that kills harmful bacteria in cuts and scrapes.