单选题Medical Journals Medical journals are publications that report medical information to physicians and other health professionals. In the past, these journals were available only in print. With the development of electronic publishing, many medical journals now have Web sites on the Internet, and some journals publish only online. A few medical journals, like the Journal of the American Medical Association, are considered general medical journals because they cover many fields of medicine. Most medical journals are specialty journals that focus on a particular area of medicine. Medical journals publish many types of articles. Research articles report the results of research studies on a range of topics varying from the basic mechanisms of diseases to clinical trials that compare outcomes of different treatments. Review articles summarize and analyze the information available on a specific topic based on a careful search of the medical literature. Because the results of individual research studies can be affected by many factors, combining results from different studies on the same topic can be helpful in reaching conclusions about the scientific evidence for preventing, diagnosing or treating a particular disease. Case conferences and case reports may be published in medical journals to educate physicians about particular illnesses and how to treat them. Editorials in medical journals are short essays that express the views of the authors, often regarding a research or review article published in the same issue. Editorials provide perspective on how the current article fits with other information on the same topic. Letters to the editor provide a way for readers of the medical journal to express comments, questions or criticisms about articles published in that journal.

单选题He accidentally found a stock of jewelry stamps when he was packing up his books.A. by the wayB. by chanceC. by handD. by nature

单选题The United States Congress and the state legislatures approve thousands of laws each year.A. amendB. debateC. passD. draft

单选题Calling for Safe Celebrations Last Fourth of July, Pete, a 14-year-old boy, was enjoying the lit-up skies and loud booms from the fireworks(烟花) being set off in his neighborhood. Suddenly, the evening took a terrible turn. A bottle rocket shot into his eye, immediately causing him terrible pain. His family rushed him to the emergency room for treatment. As a result of the injury, Pete developed glaucoma(青光眼) and cataracts(白内障). Today, Pete has permanent vision loss in his injured eye because of his bottle rocket injury. June is Fireworks Eye Safety Awareness Month, and through its EyeSmart campaign the American Academy of Ophthalmology(眼科学) wants to remind consumers to leave fireworks to professionals(专业人员). "There is nothing worse than a Fourth of July celebration ruined by someone being hit in the eye with a bottle rocket," said Dr. John C. Hagan, clinical correspondent for the Academy and an ophthalmologist at Discover Vision Centers in Kansas City. "A safe celebration means letting trained professionals handle fireworks while you enjoy the show." According to the U. S. Consumer Product Safety Commission, more than 9,000 fireworks-related injuries happen each year. Of these, nearly half are head-related injuries, with nearly 30 percent of these injuries to the eye. One-fourth of fireworks eye injuries result in permanent vision loss or blindness. Children are the most common victims of firework abuse(伤害),with those fifteen years old or younger accounting for 50 percent of fireworks eye injuries in the United States. Dr. Hagan estimates that his practice sees more than 30 injuries each year from fireworks. Even fireworks that many people consider safe represent a threat to the eyes. For children under the age of five, apparently harmless sparklers(花炮) account for one-third of all fireworks injuries. Sparklers can burn at nearly 2,000 degrees Fahrenheit(华氏).

单选题 A Biological Clock Every living thing has what scientists call a biological clock that controls behavior. The biological clock tells {{U}} {{U}} 1 {{/U}} {{/U}}when to form flowers and when the flowers should open. It tells {{U}} {{U}} 2 {{/U}} {{/U}}when to leave the protective cocoons and fly away, and it tells animals and human beings when to eat, sleep and wake. Events outside the plant and animal {{U}} {{U}} 3 {{/U}} {{/U}}the actions of some biological clocks. Scientists recently found, for example, that a tiny animal changes the color of its fur {{U}} {{U}} 4 {{/U}} {{/U}}the number of hours of daylight. In the short {{U}} {{U}} 5 {{/U}} {{/U}}of winter, its fur becomes white. The fur becomes gray brown in color in the longer hours of daylight in summer. Inner signals control other biological clocks. German scientists found that some kind of internal clock seems to order birds to begin their long migration {{U}} {{U}} 6 {{/U}} {{/U}}twice each year. Birds {{U}} {{U}} 7 {{/U}} {{/U}}flying become restless when it is time for the trip, {{U}} {{U}} 8 {{/U}} {{/U}}they become calm again when the time of the flight has ended. Scientists say they are beginning to learn which {{U}} {{U}} 9 {{/U}} {{/U}}of the brain contain biological clocks. An American researcher, Martin Moorhead, said a small group of cells near the front of the brain {{U}} {{U}} 10 {{/U}} {{/U}}to control the timing of some of our actions. These {{U}} {{U}} 11 {{/U}} {{/U}}tell a person when to {{U}} {{U}} 12 {{/U}} {{/U}}, when to sleep and when to seek food. Scientists say there probably are other biological clock cells that control other body activities. Dr. Moorhead is studying {{U}} {{U}} 13 {{/U}} {{/U}}our biological clocks affect the way we do our work. For example, most of us have great difficulty if we must often change to different work hours. {{U}} {{U}} 14 {{/U}} {{/U}}can take many days for a human body to accept the major change in work hours. Dr. Moorhead said industrial officials should have a better understanding of biological clocks and how they affect workers. He said {{U}} {{U}} 15 {{/U}} {{/U}}understanding could cut sickness and accidents at work and would help increase a factory's production.

单选题Many rich men only drive old, {{U}}unpretentious{{/U}} cars.

单选题The population of Seattle is a conglomerate of people from different ethnic and cultural backgrounds. A. a company B. a fluctuation C. an assortment D. a matching

单选题{{B}}第二篇{{/B}} {{B}} Poetry{{/B}} People seldom feel neutral about poetry(诗). Those who love it sometimes give the impression that it is an adequate substitute for food, shelter, and lobe. It isn't words, no matter how satisfying, are never an equivalent for life itself and its human experiences. Those who dislike poetry on principle sometimes claim, on the other hand, that poetry is only works and good for nothing. That's not true either. It is easy to become frustrated by words-in poetry or in life-but when words represent and recreate genuine human feelings, as they often do in poetry, they can be very important. Poetry is, in fact, more than just words. It is an experience of words, and those who know how to read poetry can easily extend their experience of life, their sense of what other people are like, their awareness of themselves, and their range of human feelings. One reason poetry can be so important is that it is so closely concerned with feelings, poetry is often full of ideas, too, and sometimes poems can be powerful experiences of the mind, but most poems are primarily about how people feel rather than how people think. Poems provide, in fact, a language for feeling, and one of poetry's most insistent merits involves its at tempt to express the inexpressible. How can anyone, for example, put into words what it means to be in love or what it feels like to lose someone one cares about? Poetry tries, and it often captures exactly the shade of emotion that feels just right to a reader. No single poem can be said to express all the things that love or death feels like, or means, but one of the joys of experiencing poetry occurs when we read a poem and want to say," Yes, that is just what it is like; I know exactly what that line means but I've never been able to express it so well." Poetry can be the voice of our feelings even when our minds are speechless with grief or joy.

单选题The Iceman On a September day in 1991, two Germans were climbing the mountains between Austria and Italy. High up on a mountain pass, they found the body of a man lying on the ice. At that height (10,499 feet, or 3,200 meters), the ice is usually permanent, but 1991 had been an especially warm year. The mountain ice had melted more than usual and so the body had come to the surface. It was lying face downward. The skeleton (骨架) was in perfect condition, except for a wound in the head. There was still skin on the bones and the remains of some clothes. The hands were still holding the wooden handle of an ax and on the feet there were very simple leather and cloth boots. Nearby was a pair of gloves made of tree bark (树皮) and a holder for arrows. Who was this man? How and when had he died? Everybody had a different answer to these questions. Some people thought that it was from this century, perhaps the body of a soldier who died in World War I, since several soldiers had already been found in the area. A Swiss woman believed it might be her father, who had died in those mountains twenty years before and whose body had never been found. The scientists who rushed to look at the body thought it was probably much older, maybe even a thousand years old. With modem dating techniques, the scientists soon learned that the Iceman was about 5,300 years old. Born in about 3300 B. C. , he lived during the Bronze Age in Europe. At first scientists thought he was probably a hunter who had died from an accident in the high mountains. More recent evidence, however, tells a different story. A new kind of X-ray shows an arrowhead still stuck in his shoulder. It left only a tiny hole in his skin, but it caused internal damage and bleeding. He almost certainly died from this wound, and not from the wound on the back of his head. This means that he was probably in some kind of a battle. It may have been part of a larger war, or he may have been fighting bandits. He may even have been a bandit himself. By studying his clothes and tools, scientists have already learned a great deal from the Iceman about the times he lived in. We may never know the full story of how he died, but he has given us important clues to the history of those distant times.

单选题I wonder what your aim in life is. A. symbol B. goal C. action D. attitude

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

单选题Accompanied by cheerful music, we began to dance.A. pleasantB. colorfulC. fashionableD. different

单选题Ulcers Even though ulcers appear to run in families, lifestyle plays more of a role than genetic factors in causing the illness, according to a report in the April 13th Journal of Internal Medicine. In particular, smoking and stress in men and the regular use of pain releasing medicines in women were linked with an increased risk of developing all ulcer. Overall, 61% of ulcer risk appears to be due to environmental factors, such as smoking, and the remaining 39% is due to genes according to Dr. Ismo Raiha of the University of Turky and colleagues at the University of Helsinki, Finland. Some researchers had suggested that families may spread Helicobacteria pylori, the bacteria that can cause ulcers. However, the new study suggests this is unlikely, according to the report. Raiha and colleagues studied data from more than 13,000 pairs of twins "to examine the roles of genetic and environmental factors in the origin of peptic ulcer disease." they explain. Both twins were more likely to develop an ulcer if the pair were genetically the same as compared with a pair of fraternal twins, suggesting that there must be some genetic susceptibility to ulcer development. However, the risk was no greater in twins living together compared with twins living apart, suggesting that shared exposure to H. pylori was not to blame. "Environmental effects were not due to factors shared by family members, and they were related to smoking and stress in men and the use of analgesics in women," the authors wrote. "The minor effects of shared environment to disease liability do not support the concept that the grouping of risk factors, such as H. pylori infection, would explain the genetic factor of peptic ulcer disease," they concluded.

单选题Gambling is lawful in Nevada.

单选题A 10-15 minutes’exercise will help you bear a heavier backpack.

单选题An Observation and an Explanation It is worth looking at one or two aspects of the way a mother behaves towards her baby. The usual fondling, cuddling and cleaning require little comment, but the position in which she holds the baby against her body when resting is rather revealing. Careful studies have shown the fact that 80 percent of mothers hold their infants in their left arms, holding them against the left side of their bodies. If asked to explain the significance of this preference most people reply that it is obviously the result of the predominance of right-handedness in the population. By holding the babies in their left arms, the mothers keep their dominant arm free for manipulations. But a detailed analysis shows that this is not the case. True, there is a slight difference between right-handed and left-handed females; but not enough to provide adequate explanation. It emerges that 83 percent of right-handed mothers hold the baby on the left side, but so do 78 percent of left-handed mothers. In other words, only 22 percent of the left-handed mothers have their dominant hands free for actions. Clearly there must be some other, less obvious explanation. The only other clue comes from the fact that the heart is on the side of the mother's body. Could it be that the sound of her heartbeat is the vital factor? And in what way? Thinking along these lines it was argued that perhaps during its existence inside the body of the mother the unborn baby get used to the sound of the heart beat. If this is so, then the re-discovery of this familiar sound after birth might have a claiming effect on the infant, especially as it has just been born into a strange and frighteningly new world. If this is so then the mother would, somehow, soon arrive at the discovery that her baby is more at peace if held on the left against her heart than on the right.

单选题Cigars Instead? Smoking one or two cigars a day doubles the risk of cancers of the lip, tongue, mouth, and throat, according to a government study. Daily cigars also increase the risk of lung cancer and cancer of the esophagus, and increase the risk of cancer of the larynx (voice box) sixfold, say researchers at the National Cancer Institute in Bethesda, Maryland. In addition, the report revealed that smoking three or four cigars a day increased the risk of oral cancer to 8.5 times the risk for nonsmokers and the risk of esophageal cancer by four times the risk of nonsmokers. The health effects of smoking cigars is one of eight sections of the article "Cigars: Health Effects and Trends". The researchers report that, compared with a cigarette, a large cigar emits up to 90 times as much carcinogenic tobacco-specific nitrosamines. "This article provides clear and invaluable information about the disturbing increase in cigar use and the significant public health consequences country, " said Dr. Richard Klausner, director of the National Cancer Institute, in a statement. "The data are clear — the harmful substances and carcinogens in cigar smoke, like cigarettes, are associated with the increased risks of several kinds of cancers as well as heart and lung diseases, " he added. "In other words, cigars are not safe alternatives to cigarettes and may be addictive. " "To those individuals who may be thinking about smoking cigars, our advice is — don't. To those currently smoking cigars, quitting is the only way to eliminate completely the cancer, heart and lung disease risks, " warned Klausner. According to a National Cancer Institute press release, there haven't been any studies on the health effects on nonsmokers at cigar social events, but "... a significant body of evidence clearly demonstrates an increased lung cancer risk from secondhand smoke. /

单选题 Single-parent Kids Do Best Single mums are better at raising their kids than two parents—at least in the bird world. Mother zebra finches have to work harder and raise fewer chicks on their own, but they also produce more attractive sons who are more likely to get a mate. The finding shows that family conflict is as important an evolutionary driving force as ecological factors such as hunting and food supply. With two parents around, there's always a conflict of interests, which can have a detrimental effect on the quality of the offspring. In evolutionary terms, the best strategy for any parent in the animal world is to find someone else to care for their offspring, so they can concentrate on breeding again. So it's normal for parents to try to pass the buck to each other. But Ian Hartley from the University of Lancaster and his team wondered how families solve this conflict, and how the conflict itself affects the offspring. To find out, they measured how much effort zebra finch parents put into raising their babies. They compared single females with pairs, by monitoring the amount of food each parent collected, and removing or adding chicks so that each pair of birds was raising four chicks, and each single mum had two—supposedly the same amount of work. But single mums, they found, put in about 25% more effort, than females rearing with their mate. To avoid being exploited, mothers with a partner hold back from working too hard if the father is being lazy, and it's the chicks that pay the price. "The offspring suffer some of the cost of this conflict," says Hartley. The cost does not show in any obvious decrease in size or weight, but in how attractive they are to the opposite sex. When the chicks were mature, the researchers tested the "fitness" of the male offspring by offering females their choice of partner. Those males reared by single mums were chosen more often than those from two-parent families. Sexual conflict has long been thought to affect the quality of care given to offspring, says zoologist Rebecca Kilner at Cambridge University, who works on conflict of parents in birds. "But the experimental evidence is not great. The breakthrough here is showing it empirically." More surprising, says Kilner, is Hartley's statement that conflict may be a strong influence on the evolution of behavior, clutch size and even appearance. "People have not really made that link," says Hartley. A female's reproductive strategy is usually thought to be affected by hunting and food supply. Kilner says conflict of parents should now be taken into account as well.

单选题This is not typical of English, but is a feature of the Chinese language.

单选题Hospital visits can be unsettling for all (51) and visitors are often unsure of how to behave at the bedside of sick friend or (52) . This may explain why so many people shy away from a hospital visit--not for fear of infection (53) rather of saying the wrong thing. By following a few simple guidelines though, embarrassment can easily be avoided. "A visit is important for a sick person because it allows them to (54) social contact," says Karl Koehle, professor at the Institute for Psychosomatics and Clinical Psychology at Cologne University. Visiting (55) , he says, can actually strengthen interpersonal relationships. "Unfortunately, many people only think of this aspect during the first few weeks." Then again, not (56) patient may want to receive visitors. So it's always advisable to arrange a visit (57) with the sick person or a close friend or relative. "That applies particularly to visits to a home, even more than in hospital," says Inge Wolff, head of the international Working Group on Etiquette in Bielefeld. But moderation is (58) . There are frequent cases of (59) ill people becoming worn (60) by an endless streams of visitors. "That's when the doctors might call a halt to it," says Koehle from experience. "And the other patients in the ward need to be taken into (61) , too," says etiquette expert Inge Wolff. They can often feel pestered by a neighbour's frequent visits. Mobile phones should always be turned off and kept out of (62) during a visit. Otherwise, the sick person could get the impression that the visitor really has no time and would like to be off as soon as an opportune moment (63) , says Wolff. (64) hospitals forbid the use of cellphones in the vicinity of hospital equipment. Visitors should take a small gift such as a newspaper or magazine, (65) a book. Sweets are tricky, says Inge Wolff, because the patient maybe under instructions to keep to a special diet. Also, the present shouldn't be too large or "over the top"-- such as a huge basket of fruit.