填空题Spacing in Animals 1．Any observant person has noticed that a wild animal will allow a man or other potential enemy to approach only up to a given distance before it flees. "Flight distance" is the terms used for this interspecies spacing. As a general rule, there is a positive relationship between the size of an animal and its flight distance—the larger the animal, the greater the distance it must keep between itself and the enemy. An antelope will flee when the enemy is as much as five hundred yards away. The wall lizard"s flight distance, on the other hand, is about six feet. Flight is the basic means of survival for mobile creatures. 2．Critical distance apparently is present wherever and whenever there is a flight reaction. "Critical distance" includes the narrow zone separating flight distance from attack distance. A lion in a zoo will flee from an approaching man until it meets a barrier that it cannot overcome. If the man continues the approach, he soon penetrates the lion"s critical distance, at which point the cornered lion reverses direction and begins slowly to stalk the man. 3．Social animals need to stay in touch with each other. Loss of contact with the group can be fatal for a variety of reasons including exposure to enemies. Social distance is not simply the distance at which an animal will lose contact with his group—that is, the distance at which it can no longer see, hear, or smell the group—it is rather a psychological distance, one at which the animal apparently begins to feel anxious when he exceeds its limits. We can think of it as a hidden band that contains the group. 4．Social distance varies from species to species. It is quite short—apparently only a few yards—among some animals, and quite long among others. 5．Social distance is not always rigidly fixed but is determined in part by the situation. When the young of apes and humans are mobile but not yet under control of the mother"s voice, social distance may be the length of her reach. This is readily observed among the baboons in a zoo. When the baby approaches a certain point, the mother reaches out to seize the end of its tail and pull it back to her. When added control is needed because of danger, social distance shrinks. To show this in man, one has only to watch a family with a number of small children holding hands as they cross a busy street.

填空题 {{B}}How Did English Become a Global Language{{/B}} The rise of English is a remarkable tale as Professor David Crystal reminds us in his attractive, short book English as a Global Language. It is certainly quite a theme. When Julius Caesar landed in Britain more than 2,000 years ago, English did not exit. Five hundred years later, English, virtually incomprehensible to modem ears, was probably spoken by about as few people as currently speak Cherokee, the language of a small North American Indian tribe and with as little influence. About 1,000 years later, at the end of the 16th century, and after the Norman Conquest, the reformation and the arrival of commercial printing technology, English was the native speech of between 5 million and 7 million people. And yet now look at it. As the second millennium approaches, English is more widely scattered, more widely spoken and written than any other language has ever been. In the title of the book it has become a truly global language. According to David Crystal, about 2.09 billion people, well over one-third of the world's population are routinely exposed to it. As he rightly points out, what is impressive about this staggering figure is "not so much the grand total but the speed with which the expansion has taken place since the 1950's. In 1950, the case for English as a world language would have been no more than plausible. Fifty years on and the case is virtually won." So what happened? Someone once said that a language is a dialect with an army and a navy. In other words, when the British navy set out to conquer the world, it set out an "army" of English speakers. As the Britishempire spread throughout the world, English became the basis of law, commerce and education. The British empire was succeeded by another (the American), which shared virtually the same linguistic heritage. American English, which has become the rocket-fuel of the English language, has magically found its way into areas undreamed of 40, let alone 400 years ago. The most valuable part of Crystal's study is the section devoted to a speedy analysis of the cultural basis of this global reach, notably the influence of broadcasting, press, advertising, popular music and film. He is also up-to-date and informative in his identification of the World-Wide-Wed as a powerful reinforce of American cultural and linguistic dominance. One of his most interesting passages concerns the role played by the League of Nations, and later the United Nations, in spreading English as an international language in the aftermath of the two world wars. What does the future hold? To this question, Crystal proposes the. recognition of a new form of English — WSSE (World Standard Spoken English) —which almost by definition rules out the possibility that English would fragment into mutually unintelligible languages as Latin once did. "English, in some shape or form, will find itself in the service of the world community forever," Crystal writes.

填空题Crime Cycles Throughout the Year Crime has its own cycles, a magazine reported some years age. Police records that were studied for five years from over 2,400 cities and towns show a surprising link between changes in the season and crime patterns. The pattern of crime has varied very little over a long period of years. Murder reaches its high during July and August, as do rape and other violent attacks. Murder, moreover, is more than seasonal: it is a weekend crime. (46) . Unlike the summer high in crimes of bodily harm, burglary has a different cycle. You are most likely to be robbed between 6 p.m. and 2 a.m. on a Saturday night in December, January or February. The most uncriminal month of all? (47) . More dog bites are reported in this month than in any other month of the year. (48) . Professor Huntington, of the Foundation for the Study of Cycles, made extensive studies to discover the seasons when people read serious books, attend scientific meetings, make the highest scores on examinations, and propose the most changes to patents, in all instances, he found a spring peak and an autumn peak separated by a summer low. On the other hand, Professor Huntington's studies indicated that June is the peak month for suicides and admissions to mental hospitals. (49) . Possibly, soaring thermometers and high humidity bring on our strange and terrifying summer actions, but police officials are not sure. "There is, of course, no proof of a connection between humidity and murder," they say. (50) . A. It is also a nighttime crime: 62 percent of murders are committed between 6 p. m. and 6 a, m. B. Because they are surprised that so many people get married in June. C. May—except for one strange statistic. D. "Why murder's high time should come in the summertime we really don't know." E. June is also a peak month for marriages! F. Apparently our intellectual seasonal cycles are completely different from our criminal tendencies.

填空题Success Stories One of the most successful fashion companies in the world is Benetton. The Benetton family opened their first shop in Italy in 1968. 1 Benetton followed four marketing principles in order to achieve their success. The first principle is Consumer Concept . To build a successful business, you have to develop products around things people value, especially quality. 2 He created clothes to match people"s wants, the style is casual; the colors and patterns are bold; and the quality is excellent. The System Link is another feature of good marketing. For Benetton, this means waiting to get information about what customers like and what they dislike before making the clothes. 3 The Information Link means making sure the company responds quickly to people"s demands. 4 This information is then sent to the main office in Italy. Benetton can use this information to identify popular products and to continue making them; it can also identify less popular products and stop making them. A final important marketing principle is the Retail Link . There are Benentton stores in countries around the world. All the stores have the same clothing, the same window displays, and the same approach to sales. 5 The things people like about Benetton stores are that the quality is always high and the prices are generally low. And that spells success. A. The founder of Benetton began by asking people what they wanted. B. There used to be a good reason for this. C. When something is sold at a Benetton store, the store records information about the type, size, and color of the item. D. Today, there are Benetton shops in major cities all over the world. E. This means that customers can go into any Benetton store in the world and be sure of what they are buying. F. In other words, Benetton"s clothes are made to order.

填空题1 From Buckingham Palace to Oxford, the UK is loaded with wonderful icons (标志)of past eras. But it has also modernized with confidence. It's now better known for vibrant (充满活力的) cities with great nightlife and attraction. Fashions, fine dining, clubbing, shopping-the UK is among the world's best. 2 Most people have strong preconceptions about the British. But if you're one of these people, you'd be wise to abandon those ideas. Visit a nightclub in one of the big cities, a football match, or a good local pub and you might more readily describe the English people as humorous and hospitable. It's certainly true that no other country in the world has more bird-watchers, sports supporters, pet owners and gardeners than the UK. 3 Getting around England is pretty easy. Budget(廉价的)airlines like Easy jet and Rynnair fly domestically. Trains can deliver you very efficiently from one major city to another. Long distance express buses are called coaches. Where coaches and buses run on the same route, coaches are more expensive (though quicker) than buses. London's famous black cabs are excellent but expensive. Minicabs are cheaper competitors, with freelance(个体的)drivers. But usually you need to give a call first. London's underground is called the Tube. It's very convenient and can get you to almost any part of the city. 4 The UK is not famous for its food. But you still need to know some of the traditional English foods. The most famous must be fish and chips. The fish and chips are deep fried in flour, English breakfast is something you need to try. It is fried bacon, sausages, fried eggs, black pudding, fried tomatoes, fried bread and baked beans, with toast and a pot of tea. Other things like shepherd's pie and Yorkshire pudding are also well-known as a part of English food culture. 5 Pubbing and clubbing are the main forms of English nightlife, especially for the young. Pubbing means going to a pub with friends, having drinks, and chatting. Clubbing is different from pubbing and includes going to a pub, or a place of music, or a bar, or any other places to gather with friends. Clubbing can be found everywhere. Usually there is some kind of dress code for clubbing, such as no jeans, no sportswear, or smart clubwear, while pubbing is much more casual.A．EducationB．PeopleC．TransportD．DrinksE. FoodF. Nightlife

填空题Messages from the Media 1 The weather forecast, a story about the candidates in an election, and movie reviews are examples of messages from the media. A communication medium, of which the plural (复数的) form is media, is a means of communicating a message. Examples of media are television, radio, newspapers, books and the telephone. The media that can reach many people at once are called mass media. 2 It is not difficult to think of other messages we receive through the mass media. Every day we get hundreds of them. Think about advertisements, for example. We see and hear these messages almost everywhere we go. Advertisements are important messages, even though they are sometimes annoying. They help us compare and evaluate products. 3 Most of us get more information from the media than from the classroom. Think, for a moment, about how you learn about local news and events. Do you depend on other people or the media? What about international news? What is the most important source of information for you? People who are asked this question usually answer, "Television". 4 Think of all the messages you received today. Perhaps you read a newspaper during breakfast, or maybe you read advertisements on billboards (露天广告牌) on your way to school. Did you listen to a weather forecast or the sports news on the radio this morning? Right now you are getting information through a very important medium of mass communication—a book. 5 We use the information we get from radio, television, newspapers, and other media to make decisions and form opinions. That is why the mass media are so important. Editorials and articles in newspapers help us decide how to vote, consumer reports on television help us decide how to spend our money, and international news on the radio makes us think and form opinions about questions of war and peace.

填空题Financial Risks Several types of financial risk are encountered in international marketing; the major problems include commercial, political, and foreign exchange risk. (46) They include solvency, default, or refusal to pay bills. The major risk, however, is competition which can only be dealt with through consistently effective management and marketing. (47) Such risk is encountered when a controversy arises about the quality of goods delivered, a dispute over contract terms, or any other disagreement over which payment is withheld. One company, for example, shipped several hundred tons of dehydrated potatoes to a distributor in Germany. (48) The alternatives for the exporter were reducing the price, reselling the potatoes, or shipping them home again, each involving considerable cost. Political risk relates to the problems of war or revolution, currency inconvertibility, expropriation or expulsion, and restriction or cancellation of import licenses. (49) Management information systems and effective decision-making processes are the best defenses against political risk. As many companies have discovered, sometimes there is no way to avoid political risk, so marketers must be prepared to assume them or give up doing business in particular market. Exchange-rate fluctuations inevitably cause problems, but for many years, most firms could take protective action to minimize their unfavorable effects. (50) International Business Machine Corportaion, for example, reported that exchange losses resulted in a dramatic 21.6 percent drop in their earnings in the third quarter of 1981. Before rates were permitted to float, devaluations of major currencies were infrequent and usually could be anticipated, but exchange-rate fluctuations in the float system are daily affairs.A．Political risk is an environmental concern for alI businesses.B．One unique risk encountered by the international marketer involves financial adjustments.C．Commercial risks are handled essentially as normal credit risks encountered in day-to-clay business.D．The distributor tested the shipment and declared it to be below acceptable taste and texture standards.E．Floating exchange rates of the world's major currencies have forced all marketers to be especially aware of exchange-rate fluctuations and the need to compensate for them in their financial planning.F．Many international marketers go bankrupt each year because of exchange-rate fluctuation.

填空题A．the timely (及时的) discoveryB．convenienceC．sex equalityD．its connection with humansE. the huge powerF. its uncertainty

填空题A. find the topic sentencesB. find out the number of wordsC. keep reading fastD. go to bed every dayE. keep a note of their reading speedF. look at your watch every few minutes

填空题Earth Angels 1 Joying Brescia was 8 years old when she noticed that cigarette butts (烟头) were littering her hometown beach in Isle of Palms, South Carolina. When she learned that it takes five years for the remains of a cigarette to disintegrate, she decided to take action. Joying launched a "No Butts on the Beach" campaign. She raised money and awareness about the need to keep the beaches clean. With the help of others, Joying also bought or received donations of gallonsize plastic ice-cream buckets. The buckets were filled with sand, and placed at all public-access areas of the beach. The buckets allowed people to dispose of their cigarettes before hitting the beach. Two years later, Joying says the buckets are full and the beach in nearly free of cigarette debris (残片). 2 People who live in or visit Steamboat Springs, Colorado, have Carter Dunham to thank for a new state wildlife refuge that preserves 20 acres of marshland and many species of wildlife. Carter and other students wrote a management plan for the area around the Yampa River. The plan was part of a class project when Carter was a freshman at Steamboat Springs High School. Working with the Colorado Division of Wildlife, Carter and his classmates mapped the area and species of animals living there. They also made decisions about, among other things, where fences and parking areas should be built. 3 Barbara Brown and her friends collect oil. It started as a project for their 4H Club after one of the girls noticed her father using motor oil to kill weeds on their farm in Victoria, Texas. They did some research and discovered that oil can contaminate ground water—a real danger in rural areas, where people live off the water on their land. The girls researched ways to recycle oil and worked with a local oil-recycling company on the issue. Now, the "Don't Be Crude" program runs oil-collection sites—tanks that hold up to 460 gallons—where people in the community can dispose of their oil. 4 Five years ago, ll-year-old Ryan Hreljac was a little boy with a big dream, for all the people in Africa to have clean drinking water. His dream began in the first grade when he learned that people were dying because they didn't have clean water, and that as little as $ 70 could build a well. "We really take water for granted," says Ryan, of Kemptville, Ontario, in Canada. "In other countries, you have to plan for it. "Ryan earned the first $ 70 by doing extra chores (零工), but with the help of others, he has since raised hundreds of thousands of dollars. His efforts led to the start of the Ryan's Well Foundation, which raises money for clean water and health-related services for people in African countries and developing countries. A Provide Clean Water B Dig Oil Wells C Save Clean Water D Don't Litter E Don't Be Crude F Protect Wildlife

填空题The Fridge 1 The fridge is considered a necessity. It has been so since the 1960s when packaged food first appeared with the label: "store in the refrigerator." 2 In my fridgeless Fifties childhood, I was fed well and healthily. The milkman came daily, the grocer, the butcher, the baker, and the ice-cream man delivered two or three times a week. The Sunday meat would last until Wednesday and surplus bread and milk became all kinds of cakes. Nothing was wasted and we were never troubled by rotten food. Thirty years on, food deliveries have ceased, fresh vegetables are almost unobtainable in the country. 3 The invention of the fridge contributed comparatively little to the art of food preservation. A vast variety of well-tried techniques already existed—natural cooling, drying, smoking, salting, sugaring, bottling... 4 What refrigeration did promote was marketing—marketing hardware and electricity, marketing soft drinks, marketing dead bodies of animals around the globe in search of a good price. 5 Consequently, most of the world"s fridges are to be found, not in the tropics where they might prove useful, but in the wealthy countries with mild temperatures where they are climatically almost unnecessary. Every winter, millions of fridges hum away continuously, and at vast expanse, busily maintaining an artificially-cooled space inside an artificially-heated house—while outside, nature provides the desired temperature free of charge. 6 The fridge"s effect upon the environment has been evident, while its contribution to human happiness has been insignificant. If you don"t believe me, try it yourself. Invest in a food cabinet and turn off your fridge next winter. You may miss the hamburgers hut at least you"ll get ride of that terrible hum.

填空题 下面的短文后2项测试任务： (1)第23～26题要求从所给的6个选项中为第2～5段第段选择1个最佳的小标题；(2)第27～30题要求所给的6个选项中选择6个选项为每个句子确定1个最佳选项。 {{B}}Museums in the Modern World{{/B}}1 Museums have changed. They are no longer places for the privileged few or for bored vacationers to visit on rainy days. Action and democracy are words used in descriptions of museums now.2 At a science museum in Ontario, Canada, you can feel your hair stand on end as harmless electricity passes through your body. At the Metropolitan Museum of Art in New York City, you can look at 17th century instruments while listening to their music. At the Modem Museum in Sweden, you can put on costumes provided by the Stockholm Opera. As these examples show, museums are reaching out, to new audiences, particularly the young, the poor, and the less educated members of the population. As a result, attendance is increasing.3 More and more, museums directors are realizing that people learn best when they can somehow become part of what they are seeing. In many science museums, for example, there are no guided tours. The visitor is encouraged to touch, listen, operate, and experiment so as to discover scientific principles for himself. He can have the experience of operating a spaceship or a computer. He can experiment with glass blowing and paper making. The purpose is not only to provide fun but also to help people feel at home in the world of science. The theory is that people who do not understand science will probably fear it, and those who fear science will not use it to best advantage. Many museums now provide educational services and children's departments. In addition to the usual displays, they also offer film showings and dance programs. Instead of being places that one "should" visit, they are places to enjoy.4 One cause of all these changes is the increase in wealth and leisure time. Another cause is the rising percentage of young people in the population. Many of these young people are college students or college graduates. They are better educated than their parents. They see things in a new and different way. They are not content to stand and look at works of art; they want art they can participate in. The same is true of science and history. In the US, certain groups who formerly were too poor to care about anything beyond the basic needs of daily life are now becoming curious about the world around them. The young people in these groups, like young people in general, have benefited from a better education than their parents received. All these groups, and the rest of the population as well, have been influenced by television, which has taught them about other places and other times.5 The effect of all this has been to change existing museums and to encourage the building of new ones. In the US and Canada alone, there are now more than 6,000 museums, almost twice as many as there were 25 years ago. About half of them are devoted to history, and the rest are evenly divided between the arts and sciences. The number of visitors, according to the American Association of museums, has risen to more than 700 million a year.6 In fact, the crowds of visitors at some museums are creating a major problem. Admission to museums has always been either free or very inexpensive, but now some museums are charging entrance fees for the first time or raising their prices. Even when raised, however, entrance fees are generally too low to support a museum, with its usually large building and its highly trained staff.

填空题 More Than 8 Hours Sleep Too Much of a Good Thing 1. Although the dangers of too little sleep are widely known, new research suggests that people who sleep too much may also suffer the consequences. 2. Investigators at the University of California in San Diego found that people who clock up 9 or 10 hours each weeknight appear to have more trouble falling and staying asleep, as well as a number of other sleep problems, than people who sleep 8 hours a night. People who slept only 7 hours each night also said they had more trouble falling asleep and feeling refreshed after a night's sleep than 8-hour sleepers. 3. These findings, which DL Daniel Kripke reported in the journal Psychosomatic Medicine, demonstrate that people who want to get a good night's rest may not need to set aside more than 8 hours a night. He added that "it might be a good idea" for people who sleep more than 8 hours each night to consider reducing the amount of time they spend in bed, but cautioned that more research is needed to confirm this. 4. Previous studies have shown the potential dangers of chronic shortages of sleep—for instance, one report demonstrated that people who habitually sleep less than 7 hours each night have a higher risk of dying within a fixed period than people who sleep more. 5. For the current report, Kripke reviewed the responses of 1,004 adults to sleep questionnaires, in which participants indicated how much they slept during the week and whether they experienced any sleep problems. Sleep problems included waking in the middle of the night, arising early in the morning and being unable to fall back to sleep, and having fatigue interfere with day-to-day functioning. 6. Kripke found that people who slept between 9 and 10 hours each night were more likely to report experiencing each sleep problem than people who slept 8 hours. In an interview, Kripke noted that long sleepers may struggle to get rest at night simply because they spend too much time in bed. As evidence, he added that one way to help insomnia is to spend less time in bed. "It stands to reason that if a person spends too long a time in bed, then they'll spend a higher percentage of time awake," he said. A. Kripke's Research Tool B. Dangers of Habitual Shortages of Sleep C. Criticism on Kripke's Report D. A Way of Overcoming Insomnia E. Sleep Problems of Long and Short Sleepers F. Classification of Sleep Problems

填空题The Paper Chase "Running a house is a lot like running a business," says Stephanie Denton, a professional organizer based in Cincinnati, Ohio, who specializes in both residential and commercial paperwork and record keeping. To get a successful grip on organizing documents, bills, and other materials, Denton suggests the following tips. Create a space in which you can always do your paperwork. This is perhaps the most important element of a successful system. If you can't devote an entire desk to the task, at least invest in a rolling file cart to store active paperwork and a two-drawer file cabinet for family records. Store the rolling file cart wherever it is most convenient and comfortable to do your work, whether that is the kitchen, office, or family room. When in doubt, throw it out. The first step to implementing a workable filing system is to eliminate paper you don't use, don't need, or that you could easily access again elsewhere. Throw out duplicate statements, old catalogs, and all of the coupons, mailings, or offerings you'll never have an opportunity to use or even read. Set aside two days a month to pay bills. If a monthly due date doesn't fit into your cycle, call up the creditor and suggest a more convenient date. Keep two manila folders at the front of your system for current bills—one to correspond with each bill-paying day—and file all incoming bills. Keep a list in the front of each folder of what needs to be paid in case the invoice never arrives or gets misplaced. Think of your filing system not as a rigid tool, but as a living, breathing system that can accommodate your changing needs. A good filing system is both mentally and physically flexible. Everyone's needs are different, says Denton, but when devising a filling system, ask yourself: "Where would I look for this?" Create main headings for your filing system, such as Investments, Taxes, Children, and so forth, and file individual folders under the main headings. Never overstuff your files.

填空题To Be an Ichthyologist An ichthyologist (鱼类学家) is a scientist who studies fish. Most people who do this love their work because it is very rewarding and varied. They work not only inside a laboratory, but also outside in field. Fieldwork includes traveling to rivers and lakes in order to collect information about specimens (样本). Reading, writing and speaking are also very important to the job. Fish scientists need to read the research of other scientists. They must be able to write up their research paper clearly so that others can follow it. They also need to be able to give lectures about their findings, so that they can spread knowledge. Ichthyologists who wish to specialize can choose any one of three areas of study. The first area is aquaculture (水产养殖). This involves the study and practice of fish farming and managing. Because it is a rather new study, there are very few job opportunities available. However, as there is so much to dig in, many think it is an exciting area for a new ichthyologist to enter. The second area is fisheries science, which means working with a team of scientists to find out most about different fish species. The third is about the protection of natural fish populations. This is important today, given that many fish are in danger of dying out because of the actions of human beings. To become a successful scientist, you need to have a curious mind and be able to work on your own. You also need to be able to handle equipment and perform experiments; but most importantly, you must love fish. To become an ichthyologist, you will need to stay at a university to pass a Bacherlor of Science degree. For this, you will need to be good at maths, physical science and biology. Then, you will need to study for another year to complete an honours degree in ichthyology. This honours degree contains coursework about all aspects of fish. You also need to complete a research paper.

填空题阅读下面的短文，文章中有5处空白，文章后面有6组文字，请根据文章的内容选择5组文字，将其分别放回文章原有位置，以恢复文章原貌。 Reduce Packaging Pressure increased recently on British supermarkets and retailers to reduce packaging as part of an anti-waste campaign. {{U}}(46) {{/U}}. Britain generates 4.6 million tons of household waste every year by packaging. Dozens of people have expressed anger at the excess of plastic wrapping. Campaigners have called on Britain to learn from other European countries. {{U}}(47) {{/U}}. When returned bottles are put in a vending machines (自动售货机), the deposit is refunded. Environmentalists warn that Britain lags behind in this. There were reports of growing unease among consumers over the amount of packaging they have to deal with. Trade standards officers also object to excessive packaging. {{U}}(48) {{/U}} In response to a campaign by Britain's The Independent newspaper, leading supermarkets have pointed to various initiatives to win the public confidence. {{U}}(49) {{/U}} But campaigners said retailers and the government could learn much from anti-waste practices on the Continent. In Sweden, non-recyclable batteries have been taxed since 1991 to encourage a switch to alternatives. {{U}}(50) {{/U}} In Germany, plastic bags are unheard of in supermarkets and deposits are paid for reusable plastic and glass beverage bottles.A．If a product is over packaged, don't buy it.B．In Belgium, when you buy something in a plastic or glass container, you make a deposit.C．This is because too much padding can give buyers a false impression of what they are buying.D．This has resulted in a 74 percent reduction in sales.E．Tesco said it was saving 112,000 tons of cardboard a year by switching to reusable plastic crates(装货箱) for transporting its fresh produce.F. The campaign was initiated by The Independent newspaper.

填空题Screen Test 1. Every year millions of women are screened with X-rays to pick up signs of breast cancer. If this happens early enough, the disease can often be treated successfully, published last year, 21 countries have screening programmes. Nine of them, including 2. But the medical benefits of screening these younger women are controversial, partly because the radiation brings a small risk of inducing cancer. Also, younger women must be given higher doses of X-rays because their breast tissue is denser. 3. Researchers at the Polytechnic University of Valencia analysed the effect of screening more than 160,000 women at 11 local clinics. After estimating the women"s cumulative dose of radiation, they used two models to calculate the number of extra cancers this would cause. 4. The mathematical model recommended by Britain"s National Radiological Protection Board(NRPB) predicted that the screening programme would cause 36 cancers per 100,000 women, 18 of them fatal. The model preferred by the UN Scientific Committee on the Effects of Atomic Radiation led to a lower figure of 20 cancers. 5. The researchers argue that the level of radiation-induced cancers is "not very significant" compared to the far larger number of cancers that are discovered and treated. The Valencia programme, they say, detects between 300 and 450 eases of breast cancer in every 100,000 women screened. 6. But they point out that the risk of women contracting cancer from radiation could be reduced by between 40 and 80 percent if screening began at 50 instead of 45, because they would be exposed to less radiation. The results of their study, they suggest, could help "optimize the technique" for breast cancer screening. 7. "There is a tradeoff between the diagnostic benefits of breast screening and its risks," admits Michael Clark of the NRPB. But he warns that the study should be interpreted with caution. "On the basis of the current data, for every 10 cancers successfully detected and prevented there is a risk of causing one later in life. That"s why radiation exposure should be minimized in any screening programme." A. Harm Screening May Do to a Younger Woman B. Investing the Effect of Screening C. Effects Predicted by Two Different Models D. Small Risk of Inducing Cancers from Radiation E. Treatment of Cancers F. Factors That Trigger Cancers

填空题The aging of cut flowers can be slowed down ______.

填空题A Major Composer Ludwig van Beethoven, a major composer of the nineteenth century, overcame many personal problems to achieve artistic greatness. Born in Bonn, Germany, in 1770, he first studied music with the court organist, Gilles van tier Eeden. His father was excessively strict and given to heavy drinking. (46) . Appointed deputy court organist to Christian Gottlob Neefe at a surprisingly early age in 1782, Beethoven also played the harpsichord and the viola. In 1792 be was sent to Vienna by his patron, Count Ferdinand Waldstein, to study music under Haydn. Beethoven remained unmarried. (47) Continually plagued by ill health, he developed an ear infection which led to his tragic deafness in 1819. (48) . He completed mature masterpieces of great musical depth: three piano sonatas, four string quartets, the Missa Solemnis, and the 9th Symphony. He died in 1827. (49) Nothing that Beethoven often flew into fits of rage, Goethe once said of him, "I am astonished by his talent, but he is unfortunately an altogether untamed personality. " (50) A．In spite of this handicap, however, he continued to write music.B．Because of irregular payments from his publishers and erratic support from his patrons, he was troubled by financial worries throughout his adult life.C．His life was marked by a passionate dedication to independence.D．When his mother died, Beethoven, then a young man, was named guardian of his two younger brothers.E．Although Beethoven's personality may have been untamed, his music shows great discipline and control, and this is how we remember him best.F．Today his music is still being played all over the world.

填空题 Volts from the Sky 1．Lightning has caused awe and wonder since old times. Although Benjamin Franklin demonstrated lightning as an enormous electrical discharge more than 200 years ago, many puzzles still surround this powerful phenomenon. 2．Lightning is generated when electrical charges separate in rain clouds, though processes are still not fully understood. Typically, positive charges build at the cloud top, while the bottom becomes negatively charged. In most instances of cloud-to-ground lightning, the negatively charged lower portion of the cloud repels negatively charged particles on the ground's surfaces, making it become positively charged, The positive charge on the ground gathers at elevated points. 3．A flow of electrons begins between the cloud and earth. When the voltage charge becomes large enough, it breaks through the insulating barrier of air, and electrons zigzag earthward. We see the discharge as lightning. 4．Lightning can occur within a cloud, between clouds, or between clouds and the ground. The first variety, intra-cloud lightning, is the most frequent but is often hidden from our view. Cloud-to -ground lightning, making up about 20 percent of lightning discharges, is what we usually see lightning comes in several forms, including sheet, ribbon, and ball, Intra-cloud lightning can illuminate a cloud so it looks like a White sheet, hence its name. When cloud-to-ground lightning occurs during strong winds, they can shift the lightning channel sideways, so it looks like a ribbon. The average lightning strike is more than 3 miles long and can travel at a tenth of the speed of light. Ball lightning, the rarest and most mysterious form, derives its name from the small luminous ball that appears near the impact point, moves horizontally, and lasts for several seconds. 5．Thunder is generated by the tremendous heat released in a lightning discharge second. This sudden heating acts as an explosion, generating shock waves we hear as thunder. 6．About 2,000 thunderstorms are occurring in the world at any time, generating about 100 lightning strikes every second, or 8 million daily. Within the United States, lightning strikes are estimated at 20 million a year, or about 22,000 per day. You have a 1-in-600,000 chance of being struck by lightning during your lifetime. Lightning can strike twice or more in the same spot. The Empire State Building in New York is struck by lightning about two dozen times annually. 7．You can measure how far you are from a lightning strike by counting the seconds between viewing the flash and hearing the bang, and then dividing by five. This approximates the mileage.