阅读理解Medicine 1. Medicine is the science and art of healing. It is a science because it is based on knowledge gained through careful study and experimentation. It is an art because it depends on how skillfully doctors and other medical workers apply this knowledge when dealing with patients. 2. The goals of medicine are to save lives, to relieve suffering, and to maintain the dignity of ill individuals. For this reason, medicine has long been one of the most respected professions. Thousands of men and women who work in the medical profession spend their lives caring for the sick. When disaster strikes, hospital workers rush emergency aid to the injured. When epidemics threaten, doctors and nurses work to prevent the spread of disease. Researchers in the medical profession continually search for better ways of fighting disease. 3. Human beings have suffered from illnesses since they first appeared on the earth. Throughout most of this time, they knew little about how the human body works or what causes disease. Treatment was based largely on superstition and guesswork. 4. However, medicine has made tremendous progress in the last several hundred years. Today, it is possible to cure, control, or prevent hundreds of diseases. People live longer than they did in the past as a result of new drugs, machines, and surgical operations. Medical progress in the control of infectious diseases, improvements in health care programs for mothers and children, and better nutrition, sanitation, and living conditions have given people a longer life expectancy. 5. As medicine has become more scientific, it has also become more complicated. In the past, doctors cared for patients almost single-handedly. Patients received treatment at home for most kinds of illnesses. Today , doctors no longer work by themselves. Instead. They head medical teams made up of nurses, laboratory workers, and many other skilled professionals. The care provided by such teams cannot generally be started at home. As a result, clinics and hospitals have become the chief centers for medical care in most countries. A. In ancient tribes, treatment was executed by witch doctors and based largely on superstition. B. Today, extensive knowledge and sophisticated medical techniques make possible the cure, control, and prevention of hundreds of disease C. The goals of medicine involve life rescuing, pain reducing, and dignity maintaining D. Control of infectious diseases is given as a reason for a longer a life E. School infirmaries appear as a result of increasing complicated medical work F. Medical care is now provided for patients in hospitals by a medical team consisting of doctors, nurses, and laboratory workers

阅读理解The short-term goal of the research is to help a person

阅读理解Modern Drugs Doctors, sixty years ago, could do little to help victims of polio. Serious cases usually ended in death. In 1955, a vaccine was developed that prevented the disease. Today, polio is no longer a major health problem. Many of the most important drugs that doctors prescribe today have been developed in the last 30 years. Modern drugs are complex, specific and powerful. People need to know more about drugs in order to use them safely. Early people discovered by accident that some of the plants growing around them seemed useful to heal sores, relieve pain, or even cure diseases. These plants were the first drugs. Now plants are still the source of some drugs. Quinine, for example, is a bitter-tasting drug used to treat the chills and fever of malaria and to reduce attacks of the disease. It is made from the bark of the cinchona tree, which grows in the Andes Mountains. The Indians of that region were the first to use the bark as a medicine. The Spanish people probably brought it to Europe in the early 1600s. Chemists learned how to get the pure drug from the bark and in 1944; it was made artificially in the laboratory. Other important drugs, such as hormones and vaccines, are obtained from animals. But most of the modern drugs come from chemical combinations worked out by research scientists. Most people never see drugs in their simple form as chemicals. Instead, they are seen as tablets, capsules or liquids that contain the drug and other ingredients. People use drugs to get different results. Some drugs attack the organism that causes a disease. They cure by killing the organism. Other drugs relieve what we call the symptoms of the disease: the headache, pain, fever or chills, and make the patient more comfortable. These constitute most over-the-counter drugs. People can get them in drug stores.

阅读理解 A. There have been many attempts to redesign the periodic table since Dmitri Mendeleev drew it up in 1871． B. Railsback has still ordered the elements according to the number of protons they have． C. “I imagine this would be good for undergraduates．” D. Railsback has listed some elements more than once． E. And the size of element’s symbol reflects how much of it is found in the Earth’s crust． F. The traditional periodic table was well drawn．

阅读理解Memory Class Stan Field knows what age can do to a person''s memory, and he''s not taking any chances with his. He chooses his food carefully and gets plenty of exercise. He also avoids stress, coca cola and cigarette smoke. What''s more, at breakfast each morning, the 69-year-old chemical engineer swallows a plateful of pills in the hope of boosting his brain power. Michelle Amove is less than half Field''s age, but no less concerned about her memory. While working round the clock to finish a degree in film studies, the 33-year-old New Yorker had the alarming sensation that she had stopped retaining anything. "I couldn''t even remember names," she says. "I thought, Oh, no, I''m over 30. It''s all downhill from here. " Besides loading up on supplements, Amove signed up for a memory enhancing course at New York''s Mount Siani Medical Center. And when she got there, she found herself surrounded by people who were just as worried as she was. For millions of Americans, and especially for baby boomers (生育高峰出生的人) , the demands of the Information Age conflict with a sense of declining physical power. "When boomers were in their 30s and 40s, they launched the fitness boom," says Cynthia Green, the psychologist who teaches Mount Sinai''s memory class. "Now we have the mental-fitness boom Memory is the boomers'' new life-crisis issue." And of course a major marketing opportunity. The demand for books and seminars has never been greater, says Jack Lannom, a longtime memory trainer whose weekly TV show, " Mind Unlimited," goes out to 33 million homes on the Christian Network. Anxious consumers are rushing to buy do-it-yourself programs and supplement makers are trying to sell everything but sawdust (木屑) as a brain booster. But before you get out your checkbook, a few questions are in order. Does everyday forgetfulness signal declining brain function? Is "megamemory" (超级记忆) a realistic goal for normal people? And if you could have a perfect memory, would you really want it? Until recently, no one could address those issues with much authority, but our knowledge of memory is exploding. New techniques are revealing how different parts of the brain interact to preserve meaningful experiences. Biologists are trying to understand the underlying (潜在的) chemical processes and neuroscientists (神经系统科学家) are discovering how age, stress and other factors can disrupt them. No one is close to finding the secret to perfect recall, but as you''ll see, that may be just as well.

阅读理解Some things we know about language Many things about language are a mystery, and many will always remain so. But some things we do know. First, we know that all human beings have a language of some sort. There is no race of men anywhere on earth so backward that it has no language, no set of speech sounds by which the people communicate with one mother. Furthermore, in historical times, there has never been a race of men without a language. Second, there is no such thing as a primitive language. There are many people whose cultures are undeveloped, who are, as we say, uncivilized, but the languages they speak are not primitive. In all known 1anguages we can see complexities that must have been tens of thousands of years in developing. This has not always been well understood; indeed, the direct contrary has often been stated. Popular ideas of the language of the American Indians will illustrate. Many people have supposed that the Indians communicated in a very primitive system of noises. Study has proved this to be nonsense. There are, or were, hundreds of American Indian languages, and all of them turn out to be very complicated and very old. They are certainly different from the languages that most of us are familiar with, but they are no more primitive five than English and Greek. A third thing we know about language is that all languages are perfectly adequate. That is, each one is a perfect means of expressing the culture of the people who speak the language. Finally, we know that language changes. It is natural and normal for language to change; the only languages which do not change are the dead ones. This is easy to understand if we look backward in time. Change goes on in all aspects of language. Grammatical features change as do speech sounds, and changes in vocabulary are sometimes very extensive and may occur very rapidly. Vocabulary is the least stable part of any language. race /n. 种族 primitive /adj. 原始的 uncivilized /adj. 不开化的，落后的 complexity /n. 复杂性，复杂现象 nonsense /n. 胡说，没有根据的话 vocabulary /n. 词汇

阅读理解Dyslexia As many as 20% of all children in the United States suffer from some form of the learning disorder2 called dyslexia. Experts on dyslexia say that the problem is not a disease. They say that persons with dyslexia use information in a different way . One of the worlds great thinkers and scientists. Albert Einstein was dyslexic. Einstein said that he never thought in words the way that most people do . He said that he thought in pictures instead. The American inventor Thomas Edison was also dyslexic. Dyslexia first was recognized in Europe and the United States more than 80 years ago. Many years passed before doctors discovered that persons with the disorder were not mentally slow or disabled. The doctors found that the brains of persons with dyslexia are different. In most people, the left side of the brain — the part that controls language is larger than the right side. In persons with dyslexia, the right side of the brain is bigger. Doctors are not sure what causes this difference. However, research has shown that dyslexia is more common in males than in females, and it is found more often in persons who are left handed4. No one knows the cause of dyslexia, but some scientists believe that it may result from chemical changes in a baby''s body long before it is born. They are trying to find ways to teach persons with dyslexia. Dyslexic persons think differently and need special kinds of teaching help. After they have solved their problems with language, they often show themselves to be especially intelligent or creative.

阅读理解Another Area of English Language Consider now another area of our language. English has a large number of nouns which appear to be neutral with regard to sex, but actually are covertly masculine. Although the dictionary may define poet as one who writes poetry, a woman who writes poetry appears so anomalous or threatening to some,that they use the special term poetess to refer to her. There is no corresponding term to call attention to the sex of a man who writes poetry, but then we find nothing remarkable in the fact that poetry is written by men. Of course, if a woman is sufficiently meritorious, we may forgive her sex and refer to her as a poet after all, or, wishing to keep the important fact of her sex in our consciousness, we may call her a woman poet. However, to balance the possible reward of having her sex overlooked, there remains the possibility of more extreme punishment, we may judge her work so harshly that she will be labelled a lady poet. Once again, the moral is clear, people who write poetry are assumed to be men until proven otherwise, and people identified as women who write poetry are assumed to be less competent than sexually unidentified (i.e., presumably male) people who write poetry. If the phenomenon we have been discussing were limited to poetry, we might not regard it as very significant , after all, our society tends to regard poets as some what odd anyway. But, in fact, it is wide spread in the language. There is a general tendency to label the exception, which in most cases turns out to be women. Many words with feminine suffixes, such as farmerette, authoress, and aviatrix, have such a clear trivializing effect, that there has been a trend away from their use and a preference for woman author and the like. The feminines of many ethnic terms, such as Negress and Jewess, are considered particularly objectionable. Other words, such as actress and waitress, seem to have escaped the negative connotations and remain in use. However, we note that waiters often work in more expensive establishments than do waitresses, that actresses belong to" Actors Equity, "and that women participants in theatrical groups have begun to refer to themselves as "actors." on rare occasions, this presumption of maleness in terms which should be sexually neutral, works to women''s advantage. If someone is called a bastard, either as a general term of abuse, or as a statement of the lack of legal marital ties between that persons parents, we assume that person is a male. While an illegitimate child may be of either sex, only men are bastard in common usage. Although the dictionary seems to regard this as a sex-neutral term, a recent dictionary of slang gives the term bastard a definition as a "female bastard."

阅读理解The Attitude For Computers As Dr. Samuel Johnson said in a different era about ladies preaching, the surprising thing about computers is not that they think less well than a man, but that they think at all. The early electronic computer did not have much going for it except a marvelous memory and some good math skills. But today the best models can be wired up to learn by experience, follow an argument, ask proper questions and write poetry and music. They can also carry on somewhat puzzling conversations. Computers imitate life. As computers get more complete, the imitation gets better. Finally, the line between the original and the copy becomes unclear. In another 15 years or so, we will see the computer as a new form of life. The opinion seems ridiculous because, for one thing, computers lack the drives and emotions of living creatures. But drives can be programmed into the computer''s brain just as nature programmed them into our human brains as a part of the equipment for survival. Computers match people in some roles, and when fast decisions are needed in a crisis, they often surpass them. Having evolved when the pace of life was slower, the human brain has an inherent defect that prevents it from absorbing several streams of information simultaneously and acting on them quickly. Throw too many things at the brain at one time and it freezes up. We are still in control, but the capabilities of computers are increasing at a fantastic rate, while raw human intelligence is changing slowly, if at all. Computer power has increased ten times every eight years since 1946. In the 1990s, when the sixth generation appears, the reasoning power of an intelligence built out of silicon will begin to match that of the human brain. That does not mean the evolution of intelligence has ended on the earth. Judging by the past, we can expect that a new species will arise out of man, surpassing his achievements as he has surpassed those of his predecessor. Only a carbon chemistry enthusiast would assume that the species must be man''s flesh-and-blood descendants. The new kind of intelligent life is more likely to be made of silicon.

阅读理解Suburb If "suburb" is meant an urban margin that grows more rapidly than its already developed interior, the process of suburbanization began during the emergence of the industrial city, in the second quarter of the nineteenth century. Before that period the city was a small, highly compact cluster in which people moved about on foot, and goods were conveyed by horse and cart. But the early factories, built in the 1830''s and 1840''s, were located along waterways and near railheads at the edges of cities, and housing was needed for the thousands of people drawn by the prospect of employment. In time, the factories were surrounded by proliferating mill towns of apartments and row houses around the older, main cities. As a defence against this encroachment, and to enlarge their tax bases, the cities appropriated their industrial neighbors. In 1854 for example, the city of Philadelphia annexed most of Philadelphia County. Similar municipal maneuvers took place in Chicago and in New York. Indeed, most great cities of the United States achieved such status only by incorporating the communities along their borders. With the acceleration of industrial growth come acute, urban crowding and accompanying social stress-conditions began to approach disastrous proportions when, in 1888, the first commercially successful electric traction line was developed. Within a few years the horse-drawn trolleys were retired and electric streetcar networks crisscrossed and connected every major urban area, fostering a wave of suburbanization that transformed the compact industrial city into a dispersed metropolis. This first phase of mass-scale suburbanization was reinforced by the simultaneous emergence of the urban middle class, whose desires for homeownership in neighborhoods far from the aging inner city were satisfied by the developing of single-family housing tracts.

阅读理解Food Many Americans harbour a grossly distorted and exaggerated view of most of the risks surrounding food. Fergus Clydesdale, head of the department of food science and nutrition at the university of Massachusetts Amherst, says bluntly that if the dangers from bacterially contaminated chicken were as great as some people believe. "The streets would be littered with people lying here and there." Though the public increasingly demands no-risk food, there is no such thing. Bruce Ames, chairman of the biochemistry department at the University of California, Berkeley, points out that up to 10% of a plant''s weight is made up of natural pesticides(杀虫剂) . Says he; "Since plants do not have jaws or teeth to protect themselves, they employ chemical warfare. " And many naturally produced chemicals, though occurring in tiny amounts, prove in laboratory tests to be strong carcinogens—a substance which can cause cancer. Mushrooms (蘑菇) might be banned if they were judged by the same standards that apply to food additives (添加剂). Declares Christina Stark, a nutritionist at Cornell University:" We''ve got far worst natural chemicals in the food supply than anything man-made. " Yet the issues are not that simple. While Americans have no reason to the terrified to sit down at the dinner table, they have every reason to demand significant improvements in food and water safety. They unconsciously and unwillingly take in too much of too many dangerous chemicals. If food already contains natural carcinogens, it does not make much sense to add dozens of new man-made ones. Though most people will withstand the small amounts of contaminants generally found in food and water, at least a few individuals will probably get cancer one day because of what they eat and drink. To make good food and water supplies even better, the Government needs to tighten its regulatory standards, stiffen its inspection program and strengthen its enforcement policies. The food industry should modify some long-accepted practices or turn to less hazardous alternatives. Perhaps most important, consumers will have to do a better job of learning how to handle and cook food properly. The problems that need to be tackled exist all along the food-supply chain, from fields to processing plants to kitchens.

阅读理解Which of the following is not true 0f Britain?

阅读理解Genetically modified products are not popular in Mexico

阅读理解Regeneration of Limbs Most people would agree that it would be wonderful if humans could regenerate limbs. Those who have lost their arms or legs would be complete again. The day is still far off when this might happen. But in the last 10 years, doctors have reported regeneration in smaller parts of the body, most often fingers. Regeneration is not a newly-discovered process. For centuries, scientists have seen it work in some kinds of animals. Break off a lizards (蜥蜴的) tail, for example, and it will grow a new tail. Scientists now are looking for a way to turn on this exciting ability in more highly-developed animals, including humans. Their experiments show that nerves, cell chemistry and the natural electric currents in the body all seem to have a part in this process. The body of every animal contains general purpose cells that change into whatever kind of cells the body needs. Animals such as the lizard or salamander (蝾螈) use these cells to regenerate a new tail or leg when the old one is broken off. These cells collect around the wound. They form a mass called a blastema (胚基). The cells of the blastema begin to change. Some become bone cells, some muscle cells, some skin cells. Slowly, a new part re-grows from the body outward. When completed, the new part is just like the old one. More than 200 years ago, Italian scientist Luigi Spallanzani showed that younger animals have a greater ability to regenerate lost parts than older animals. So do animals lower on the ladder of evolutionary development. The major difference seems to be that less-developed animals have more nerves in their tails and legs than humans do in their arms and legs. Another helpful piece of information was discovered in the late 1800s. Scientists found that when a creature is injured, an electrical current flows around the wound. The strength of the current depends on how severe the wound is and on how much nerve tissue is present. In 1945, American scientist Meryl Rose tested another idea about regeneration. He thought a new limb might grow only from an open wound. Doctor Rose cut off the front legs of some frogs, below the knee. He kept the wounds wet with a strong salty liquid. This prevented skin from growing over the wounds. The results were surprising. Frogs do not regenerate new legs naturally. But these frogs began to grow new limbs. About half of each cut-off leg grew back again. New bones and muscles developed. This research has led doctors to new ways of treating cut-off fingers. Doctors have observed, for example, that many children and some adults will re-grow the top of a finger if the wound is left open.

阅读理解When did British gentlemen begin to wear ties regularly？

阅读理解Cancer 1. Cancer, which may arise from any type of cell and in any body tissue, is not a single disease but a large number of diseases classified according to the tissue and type of cell of origin. Several hundred such classes exist, constituting three major subtypes; sarcomas, carcinomas, leukemias and lymphomas. 2. A number of factors produce cancer in a proportion of exposed individuals. Among these factors are heredity, viruses, ionizing(离子)radiation, chemicals, and alterations in the immune system. For a long time these various factors seemed to work in different ways, but now researchers are studying how they might interact. 3. More than 1,350,000 new cases of cancer occur in the United States each year. It is the second leading cause of death in the nation, accounting for about 550,000 deaths annually. The incidence of cancer varies enormously among different geographic areas. The age-adjusted death rate from all cancers in males is 310. 9 per 100,000 in Luxembourg (the highest) as Compared to 37. 5 in El Salvador (the lowest). For women it is 175.2 in Denmark and 48.7 in El Salvador. The figures for the United States are 216. 6 per 100,000 men and 136.5 per 100,000 women. 4. The principal approach to curing cancer is to remove all of the malignant (恶性的) cells by a surgical operation. In the past this meant the removal of all of the involved tissue and as much tumors, notably cancer of the breast, this is not always necessary. However, it may help to relieve symptoms. 5. The most important preventive measure in controlling cancer is stopping tobacco use, which is the cause of 30 percent of all deaths from cancer. A large reduction might follow better diet: optimal (适当的)calorie intake to avoid obesity (肥胖), reduction of calories form fat to 20 percent of the diet, reduction of redmeat intake, and increased intake of dietary fiber and protective foods. A. Causes of cancer B. Types of cancer C. Control cancer D. The attitude faced to cancer E. Mortality Rate from cancer F. Treating cancer by surgery

阅读理解People, Customs and Habits 1. Every ten years the United States makes a complete count, or census, of its people. When the first count was made in 1790, the new nation had fewer than 4 million people, almost all living along the East Coast. Today, there are more than 226 million. 2. We moved slowly through the city and entered a slum district. The streets crowded with people. People eating, people washing, people sleeping. People visiting each other, arguing and screaming. People pushing their hands through the taxi windows begging. People holding on to the sides of buses. People, people, people, people. 3. We have the ability to keep what we have learned in our minds so that we can call it up again for use later on. What we remember in this way may be words, figures, dates, poetry, events in our own lives and things like arithmetic or historic facts, and even skilled actions such as playing the piano or riding a bicycle. 4. Different countries and different races have different manners. Before entering a house in some Asian countries, it is good manners to take off your shoes. In European countries, even though shoes sometimes become very muddy, this is not done. A guest in a Chinese house never finishes a drink. He leaves a little, to show that he has had enough. In England, a guest always finishes a drink to show that he has enjoyed it. 5. Many visitors find the fast pace at which Americans move very troubling. They always appear to be hurrying to get where they are going and are very impatient if they are delayed even for a brief moment. A. Population B. Over Population C. Memory D. Customs E. Rush F. Census