填空题 The Supercomputer Network 1. Recently ten laboratories run by governments in different parts of the world have become linked. Their computers have been connected so they can "talk" to each other. This may not seem very dramatic news, but it is the beginning of a development that will increase the power of the Internet tremendously. 2. The Internet is an interconnected (互联) system of networks that connects computers round the world and facilitates the transmission and exchange of information. The way that you use the Internet is by accessing this network. This depends on the power that your system allows you to use. The power of your computer is responsible for how fast you can download (下载) files, how much data you can store, etc. If your computer is old and slow, accessing the information can be very difficult. 3. The new development in information technology has been called "the grid" (网格技术), and it will be a network of computers that are linked together. The "grid" will work in a different way from the Internet, enabling you to get the power of the biggest computers in the world on your computer. Accessing the information will no longer depend on the power of your computer. The idea is that while you access information, you will also have access to the power of the bigger computer stations. 4. One advantage of this revolutionary idea is that geographical location will become irrelevant. The "grid" will decide which are the best parts of a worldwide network to do the job you want. This means that you may be accessing a computer in Japan to solve a problem in Alaska. 5. The "grid" can be compared to having an efficient personal assistant. You can give your assistant a task and "he" will do it for you. The assistant will do the preliminary research, collect the data, compare them and decide on the best course of action by accessing any of the computer centres in the "grid" that happen to have the relevant information. All you have to do is assign the task, sit back and wait. 6. At present, possible applications of the "grid" in scientific research are being explored. While it has taken about fifteen years for Internet use to become widespread, experts believe that the "grid" could be up and running for private individuals far more quickly. Scientists working on "grid" projects are convinced that it will be as widely used as the web in the next ten years. A. How does the "grid" work? B. Power shared C. Just make a request D. Limitations of present Internet use E. Distance is not a problem F. A new era for the Internet

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。 {{B}}The Importance of Agriculture in China{{/B}} The development of agriculture and the balance between food and population are China’s fundamental economic problems. The classical histories praise emperors for devotion to agriculture and much of China’s modern history is{{U}} (46) {{/U}}, which has been growing steadily. Today, although agriculture accounts for only a quarter of the Gross National Product, it is still the main determinant of the standard of living and the principal occupation of at least 70 percent of the population. Agriculture also{{U}} (47) {{/U}}because industry needs both agricultural raw materials and food for its work force. The failure of agriculture to supply raw materials and food halted and later reversed the industrial progress of the 1950’s. After 1960 new emphasis was placed on agriculture, and the slogan “Agriculture is the foundation of the economy” has remained a central Chinese economic policy ever since. {{U}} (48) {{/U}}, there is an indirect link due to the relationship between agriculture and foreign trade. Many of China’s exports are{{U}} (49) {{/U}}or consumer goods based on them. Flourishing agriculture, therefore, promotes exports. It also reduces the need to spend foreign exchange on imports of grain and cotton, therefore{{U}} (50) {{/U}}. A. determines the progress of industry B. the story of the unfolding struggle to feed a peasant population C. either agricultural raw materials D. enlarging the capacity of the economy to import machinery and commodities for industry E. In addition to the direct links between agriculture and industry F. thus promoting both import and export

填空题Technology Transfer in Germany When it comes to translating basic research into industrial success, few nations can match Germany. Since the 1940s, the nation"s vast industrial base has been fed with a constant stream of new ideas and expertise from science. And though German prosperity(繁荣)has faltered(衰退)over the past decade because of the huge cost of unifying east and west as well as the global economic decline, it still has an enviable(令人羡慕的)record for turning ideas into profit. Much of the reason for that success is the Fraunhofer Society, a network of research institutes that exists solely to solve industrial problems and create sought-after technologies. But today the Fraunhofer institutes have competition. Universities are taking an ever larger role in technology transfer, and technology parks are springing up all over. These efforts are being complemented by the federal programs for pumping money into start-up companies. Such a strategy may sound like a recipe for economic success, but it is not without its critics. These people worry that favoring applied research will mean neglecting basic science, eventually starving industry of flesh ideas. If every scientist starts thinking like an entrepreneur(企业家), the argument goes, then the traditional principles of university research being curiosity-driven, free and widely available will suffer. Others claim that many of the programs to promote technology transfer are a waste of money because half the small businesses that are promoted are bound to go bankrupt within a few years. While this debate continues, new ideas flow at a steady rate from Germany"s research networks, which bear famous names such as Helmholtz, Max Planck and Leibniz. Yet it is the fourth network, the Fraunhofer Society, that plays the greatest role in technology transfer. Founded in 1949, the Fraunhofer Society is now Europe"s largest organization for applied technology, and has 59 institutes employing 12,000 people. It continues to grow. Last year it swallowed up the Heinrich Hertz Institute for Communication Technology in Berlin. Today, there are even Fraunhofers in the US and Asia.

填空题 The Mysteries of Nazca In the desert of Peru, 300 kilometers from Lima, one of the most unusual artworks in the world has mystified (迷惑) people for decades. {{U}} {{U}} 1 {{/U}} {{/U}}But from high above, these marks are huge images of birds, fish, seashells, all beautifully carved into the earth. The Nazca lines are so difficult to see from the ground that they weren't discovered until the 1930s, when pilots spotted them while flying over the area. In all, there are about 70 different human and animal figures on the plain, along with 900 triangles, circles, and lines. Researchers have figured out that the lines are at least 1,500 years old, but their purpose is still a mystery. {{U}} {{U}} 2 {{/U}} {{/U}}However, it would probably be very tricky to land and a spaceship in the middle of pictures of dogs and monkeys. In the 1940s, an American explorer named Paul Kosok suggested that the drawings are a chronicle (记录) of the movement of the stars and planets. {{U}} {{U}} 3 {{/U}} {{/U}}Later, an astronomer tested his theory with a computer, but he couldn't find any relation between the lines and movements in space. Another explanation is that the lines may have been made for religious reasons. British researcher Tony Morrison investigated the customs of people in the Andes Mountain and learned that they sometimes pray by the side of the road. It's possible that in the past, the lines of Nazca were created for a similar purpose. {{U}} {{U}} 4 {{/U}} {{/U}}But the local people have never constructed anything this big. Recently, two other scientists, David Johnson and Steve Mabee, have speculated that lines could have been related to water. Nazca is one of the driest places in the world and receives only 2cm of rain every year. While Johnson was searching for ancient water sources in the area, he noticed that some waterways built ancient people were connected with the lines. Johnson believes that the Nazca lines are a giant map underground water in the area. {{U}} {{U}} 5 {{/U}} {{/U}} A. A Swiss writer named Erich von Daniken wrote that the Nazca lines were designed as a landing place for UFOs. B. Other scientists are now searching for evidence to prove this. C. Seen from the ground, it looks like lines scratched into the earth. D. He called Nazca "the largest astronomy book in the world". E. Scholars differ in interpreting the purpose of the designs. F. The largest picture may have been the sites for special ceremonies.

填空题Ludwig Van Beethoven 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 der 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 he 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) . Noting 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 musicB. Because of irregular payments from his publishers and erratic support from his patrons, he was troubled by financial worries throughout his adult lifeC. His life was marked by a passionate dedication to independenceD. When his mother died, Beethoven, then a young man, was named guardian of his two younger brothersE. Although Beethoven's personality may have been untamed, his music shows great discipline and control, and this is how we remember him bestF. Today his music is still being played all over the world

填空题A. Building materialsB. Need of greater building varieties in modern lifeC. Restoration of ancient civilizationsD. Evolution in styleE. factors affecting modem architectureF. A social art

填空题Intelligence: a Changed View 1. Intelligence was believed to be a fixed entity(存在，实体), some faculty of the mind that we all possess and which determines in some way the extent of our achievements. Its value therefore, was as a predictor of children"s future learning. If they differed markedly in their ability to learn complex tasks, then it was clearly necessary to educate them differently and the need for different types of school and even different ability groups within school was obvious. Intelligence tests could be used for streaming(分组) children according to ability at an early age; and at 11 these tests were superior to measures of attainment for selecting children for different types of secondary education. 2. Today, we are beginning to think differently. In the last few years, research has thrown doubt on the view that innate intelligence can ever be measured and on the very nature of intelligence itself. There is considerable evidence now which shows a great influence of environment both on achievement and intelligence. Children with poor home backgrounds not only do less well in their school work and intelligence tests but their performance tends to deteriorate gradually compared with that of their more fortunate classmates. 3. There are evidences that support the view that we have to distinguish between genetic intelligence and observed intelligence. Any deficiency in the appropriate genes will restrict development no matter how stimulating the environment. We cannot observe and measure innate(内在的) intelligence, whereas we can measure the effects of the interaction(相互作用) of whatever is inherited with whatever stimulation has been received from the environment. Researches have been investigation what happens in this interaction. 4. Two major findings have emerged from these researches. Firstly, the greater part of the development of observed intelligence occurs in the earliest years of life. It is estimated that 50 per cent of measurable intelligence at age 17 is already predicable by the age of four. Secondly, the most important factors in the environment are language and psychological aspects of the parent-child relationship. Much of the difference in measured intelligence between "privileged" and "disadvantaged" children may be due to the latter"s lack of appropriate verbal stimulation (激发，促进) and the poverty of their perceptual experiences. 5. These research findings have led to a revision in our understanding of the nature of intelligence. Instead of it being some largely inherited fixed power of the mind, we now see it as a set of developed skills with which a person copes with any environment. These skills have to be learned and, indeed, one of them is learning how to learn. 6. The modern ideas concerning the nature of intelligence are bound to have some effect on our school system. In one respect a change is already occurring. With the move toward comprehensive education and the development of unstreamed classes, fewer children will be given the label "low IQ" which must inevitably condemn a child in his own, if not society s eyes. The idea that we can teach children to be intelligent in the same way that we can teach them reading or arithmetic is accepted by more and more people.

填空题 下面的短文后有2项测试任务： (1)第23～26题要求从所给的6个选项中为第2～5段每段选择1个最佳标题； (2)第27～30题要求从所给的6个选项中为每个句子确定1个最佳选项。 Memory Test 1 "I am going to give you five techniques that will enable you to remember anything you need to know at school," promised lecturer lan Robinson to a hundred schoolchildren. He slapped his hand down on the table. "When I've finished in two hours' time, your work will be far more effective and productive. Anyone not interested, leave now. " The entire room sat still. 2 Robinson calls himself the Mind Magician (魔术师). He specializes in doing magic tricks that look totally impossible, and then he reveals that they involve nothing more mysterious than good old-fashioned trickery (骗术). "I have always been interested in tricks involving memory—being able to reel off (一口气说出) the order of cards in a pack, that sort of thing," he explains. 3 Robinson was already lecturing to schools on his magic techniques when it struck him that students might find memory techniques even more valuable. "It wasn't difficult area to move into, as the stuffs all there in books. " So he summarized everything to make a two-hour lecture about five techniques. 4 "You want to learn a list of a hundred things? A thousand? No problem, " says Robinson. The scandal is that every child is not taught the techniques from the beginning of their school life. The schoolchildren who were watching him thought it was brilliant. "I wish I'd been told this earlier," commented Mark, 'after Robinson had shown them how to construct "mental journeys". 5 Essentially, you visualize (想象) a walk down a street, or a trip round a room, and pick the points where you will put the things you want to remember-the lamppost, the fruit bowl. Then in each location you put a visual representation of your list-phrasal verbs, historical dates, whatever-making them as strange as possible. It is that simple, and it works. 6 The reaction of schools has been uniformly enthusiastic. "The pupils benefited enormously from Lan's presentation," says Dr. Johnston, head of the school where Robinson was speaking. "Ideally we should run a regular class in memory techniques so pupils can pick it up gradually. " A. Good results B. An ancient skill C. Gaining attention D. Memory tricks E. A lecture on memory techniques F. Ways to improve memory

填空题Various Dictionaries You"re probably most familiar with college dictionaries, often called abridged dictionaries. Although abridged means "shortened", these dictionaries contain more than 150,000 entries and provide detailed definitions that are sufficient for most college students and general users. College dictionaries also contain separate lists of abbreviations, biographical and geographical names, foreign words and phrases, and tables of measures. Webster"s Ⅱ New Riverside University Dictionary and the American Heritage Dictionary of the English Language are college dictionaries. Unabridged dictionaries contain as many as 500,000 entries and provide detailed definitions and extensive word histories (etymologies). These dictionaries, possibly in several volumes and mostly found in libraries, are excellent sources for scholarly inquiries. Unabridged dictionaries include the Oxford English Dictionary and the Random House Dictionary of the English Language. A dictionary entry has many elements: multiple definitions, syllabication, preferred spelling and pronunciation (some words have more than one acceptable spelling and pronunciation), and part-of-speech labels. Some entries also include plurals and capitalized forms, synonyms, antonyms, and derivatives. Americanisms and etymologies may be provided along with usage notes, cross-references, and idioms. If you prefer using the dictionary on a computer, you can obtain CD-ROM versions of many major dictionaries. In addition, you can access numerous dictionaries, such as WWWebster"s Dictionary, on the Internet. Online dictionaries allow you to enter a search word (you even get help with spelling) to see a definition, and sometimes even an illustration. Online dictionaries also offer additional features, such as word games, language tips, and amusing facts about words. Some online dictionary services allow you to access numerous dictionaries, both general and specialized, in one search. Specialized dictionaries provide in-depth information about a certain field. For example, there are dictionaries for the specialized vocabularies of law, computer technology, and medicine. In addition, there are dictionaries of synonyms, clichés, slang, and even regional expressions, such as the Dictionary of American Regional English (DARE). There are also dictionaries of foreign languages, famous people"s names, literary characters" names and place names.

填空题 Cloning (克隆): Future Perfect? 1. A clone is an exact copy of a plant or animal produced from any one cell. Since Scottish scientists reported that they had managed to clone a sheep named Dolly in 1997 research into cloning has grown rapidly. In May 1998, scientists in Massachusetts managed to create WTO identical calves (牛犊) using cloning technology. A mouse has also been cloned successfully, but the debate over cloning humans really started when Chicago physicist Richard Seed made a surprising announcement: "We will have managed to clone a human being within the next two years," he told the world. 2. Seed's announcement provoked a lot of media attention, most of it negative. In Europe, nineteen nations have already signed an agreement banning human cloning and in the U.S. the President announced: "We will be introducing a law to ban any human cloning and many states in the U.S. will have passed anti--cloning laws by the end of the year." 3. Many researchers are not so negative about cloning. They are worried that laws banning human cloning will threaten important research. In March, The New England Journal of Medicine called any plan to ban research on cloning humans seriously mistaken. Many researchers also believe that in spite of attempts to ban it, human cloning will have become routine by 2010 because it is impossible to stop the progress of science. 4. Is there reason to fear that cloning will lead to a nightmare world? The public has been bombarded (轰炸) with newspaper articles, television shows and films, as well as cartoons. Such information is often misleading, and makes people wonder what on earth the scientists will be doing next. 5. Within the next five to ten years scientists will probably have found a way of cloning humans. It could be that pretty soon we will be able to choose the person that we want our child to look like. But how would it feel to be a clone among hundreds, the anti-cloners ask. Pretty cool, answer the pro-cloners (赞成克隆的人). A. Strong Reactions B. Anxiety about the Future of Cloning C. The Right to Choose D. What is Cloning? E. Arguments in Favor of Cloning F. A Common Sight

填空题Adult Education 1. Voluntary learning in organized courses by mature men and women is called adult education. Such education is offered to make people able to enlarge and interpret their experience as adults. Adults may want to study something which they missed in earlier schooling, get new skills or job training, find out about new technological developments, seek better self—understanding, or develop new talents and skills. 2. This kind of education may be in the form of self-study with proper guidance through the use of libraries, correspondence courses, or broadcasting. It may also be acquired collectively in schools and colleges, study groups, workshops, clubs, and professional associations. 3. Modern adult education for large numbers of people started in the 18th and 19th centuries with the rise of the Industrial Revolution. Great economic and social changes were taking place, people were moving from rural areas to cities, new types of work were being created in an expanding factory system. These and other factors produced a need for further education and re-education of adults. 4. The earliest programs of organized adult education arose in Great Britain in the 1790s, with the founding of an adult school in Nottingham and a mechanics institute in Glasgow. The earliest adult education institution in the United States was founded by Benjamin Franklin and some friends in Philadelphia in 1727. 5. People recognize that continued learning is necessary for most forms of employment today. For example, parts of the adult population in many countries find it necessary to take part in retraining programs at work or even to learn completely new jobs. Adult education programs are springing up constantly to meet these and other needs.

填空题 下面的短文后有2项测试任务：(1)第23～26题要求从所给的6个选项中为第1～4段每段选择1个最佳标题；(2)第27～30题要求从所给的6个选项中为每个句子确定1个最佳选项。 {{B}} Teach Your Child Science{{/B}}1 It is important to make your child interested in science from an early age. Most young children ask a lot of questions and you should give careful scientific answers. Don't only give facts, but try to give explanations as well.2 Science is not just knowledge; it is a way of thinking, a method of finding out about the world. We see something. We try to explain it, and we test our idea by setting up an experiment. One day you come home and find the plant on the table has fallen over. You think it might be the wind from the open window or the cat, so you close the window, but leave the cat in and see what happens (you can also try leaving the window open and shutting the cat out). Of course, you remember there may be a third explanation.3 Ask your child to get a piece of string, some salt, a glass of water and an ice cube (冰块). Tell her to put the ice in the water, and then put one end of the string on the ice, leaving the other end over the side of the glass. Put a little salt on the ice. Wait a minute, and then pull the string; it should be attached to the ice. Ask the child: "What has happened?"4 Probably she won't know. Ask her whether fresh water or salt water freezes into ice first. If you live near the sea and have a cold winter, she should know fresh water freezes first as she will have seen that happen. Show her how to test the idea by half-filling two paper cups with water, adding salt to one. Then put them in the icebox and check every three minutes. Write the results in a table. The conclusion will be that salt changes the behaviour of water. Thinking about the string, we see the salt turned some of the ice into water. Then the salt went away into the water and the ice froze again leaving the string attached.5 Then you can ask, "Will water with salt boil at the same temperature as water without salt?" She can think, tell you her idea and you can test it in the kitchen. (take care because of the heat)

填空题Memory Test 1. "I am going to give you five techniques that will enable you to remember anything you need to know at school,"promised lecturer lan Robinson to a hundred schoolchildren.He slapped his hand down on the table."When I've finished in two hours' time,your work will be far more effective and productive.Anyone not interested,leave now."The entire room sat still. 2. Robinson calls himself the Mind Magician (魔术师).He specializes in doing magic tricks that look totally impossible,and then he reveals that they involve nothing more mysterious than good old-fashioned trickery (骗术)."I have always been interested in tricks involving memory-being able to reel off (一口气说出) the order of cards in a pack,that sort of thing,"he explains. 3. Robinson was already lecturing to schools on his magic techniques when it struck him that students might find memory techniques even more valuable."It wasn't difficult area to move inot,as the stuff's all there in books."So he summarized everything to make a two-hour lecture about five techniques. 4. "You want to learn a list of a hundred things?A thousand?No problem,"says Robinson.The scandal is that every child is not taught the techniques from the beginning of their school life.The schoolchildren who were watching him thought it was brilliant."I wish I'd been told this earlier,"commented Mark,after Robinson had shown them how to construct"mental journeys". 5. Essentially,you visualize (想象) a walk down a street,or a trip round a room,and pick the points where you will put the things you want to remember-the lamppost,the fruit bowl.Then in each location you put a visual representation of your list-phrasal verbs,historical dates,whatever-making them as strange as possible.It is that simple,and it works. 6. The reaction of schools has been uniformly enthusiastic."The pupils benefited enormously from lan's presentation,"says Dr Johnston,head of the school where Robinson was speaking."ldeally we should run a regular class in memory techniques so pupils can pick it up gradually."A. Good resultsB. An ancient skillC. Gaining attentionD. Memory tricksE. A lecture on memory techniquesF. Ways to improve memory

填空题A do whatever they like for relaxation B where you can play all kinds of ball games C than the world famous Broadway D enjoy the colorful night life of the city E where the wealthy people would go shopping F for what seems to be a very small sum today

填空题 Natural Gas 1. Natural gas is produced from reservoirs deep beneath the earth's surface. It is a fossil fuel, meaning that it is derived from organic material buried in the earth millions of years ago. The main component of natural gas is methane. 2. The popularity and use of clean natural gas has increased dramatically over the past 50 years as pipeline infrastructure has been installed to deliver it conveniently and economically to millions of residential, commercial and industrial customers worldwide. Today, natural gas services available in all 50 states in the U.S., and is the leading energy choice for fueling American homes and industries. More than 65 million American homes use natural gas. In fact, natural gas is the most economical source for home energy needs, costing one-third as much as electricity. In addition to heating homes, much of the gas used in the United States is used as a raw material to manufacture a wide variety of products, from paint to fibers for clothing, to plastics for healthcare, computing and furnishings. Natural gas is also used in a significant number of new electricity-generating power plants. 3. Natural gas is one of the safest and cleanest fuels available. It emits less pollution than other fossil fuel sources. When natural gas is burned, it produces mostly carbon dioxide and water vapour—the same substances emitted when humans exhale. Compared with some other fossil fuels, natural gas emits the least amount of carbon dioxide into the air when combusted, making natural gas the cleanest burning fossil fuel of all. 4. The United States consumes about one-third of the world's natural gas output, making it the largest gas-consuming region in the world. The U.S. Department of Energy Information Administration forecasts that natural gas demand will grow by more than 50 percent by 2025. 5. There are huge reserves of natural gas beneath the earth's surface. The largest reserves of natural gas can be found in Russia, West and North Africa and the Middle East. LNG has been produced domestically and imported in the United States for more than four decades. Today, the leading imports of LNG are Japan, Korea, France and Spain.

填空题A. the nucleus of a cellB. cloned human beingsC. a human being in two yearsD. a law to ban human cloningE. a report on human cloningF. heavy media coverage

填空题 A Star Is Born 1. The VLT (Very Large Telescope) is the world's largest telescope (望远镜) and is taking astronomers (天文学家) further back to the Big Bang than they ever thought possible. Located 2,600 metres up to the Chilean Andes, it has four huge mirrors, each about the size of a London bus. The VLT is so powerful it can spot a burning match 10,000 kilometres away. 2. This astonishing power will allow astronomers to see events in space from the birth of stars to the collision (碰撞) of galaxies (星系) on the edge of the cosmos (宇宙). The VLT is giving astronomers their best-ever view of the cosmos. The power of the VLT to see the smallest detail at the furthest distances makes its designers amazed. 3. Take the case of Eta Carinae, one of the most explosive stars in the universe. This star produces ultraviolet laser rays (紫外线) and it will destroy itself in a few million years' time. It is five times brighter than the sun and when it explodes it is going to be a sight worth waiting for! 4. But it is at distances of millions, even billions, of light years that the VLT really shows its power. The VLT can detect light that set out on its journey before the earth even existed. This gives astronomers their first- ever detailed views of events that took place in the earliest days of the cosmos. 5. In other words, the VLT is a kind of a time machine. It takes astronomers back to a time when complete galaxies crashed into each other. The effects of these past collisions can now be seen by scientists, and astronomers believe the telescope will reveal more about these exciting events in the years to come. One day, we might be able to say we have traveled back to the beginning of time, and we will have a much clearer picture of how our planet was born. A. Enents that Took Place before the Earth Existed B. Power of the Telescope C. Details of Eta Carinae D. Invention of a Time Machine E. Biggest Telescope

填空题Rainmaking 1. The idea of rainmaking is almost as old as man, but it was not until 1946 that man succeeded in making rain. In ancient times, rainmakers had claimed to bring rain by many methods: dancing singing, killing animals (including humans). 2. For a long time, men have understood where rain comes from. Water from the surface of oceans and lakes becomes part of the air, where it forms clouds from which rain falls. But exactly what starts the formation of raindrops was not known until quite recently. A man named John Aitken proved that drops of water gather around tiny bits of dust or other matter. The centers of the drops are so small that the human eye cannot see them. Without such centers, it seems raindrops do not form. 3. During World War Ⅱ, Dr. Irving Langmir, and his assistant Schaefer, were hired by the General Electric Company to study how and why ice forms on the wings of airplanes. They went to a mountain in New Hampshire, where snowstorms are common and cold winds blow. They were surprised to find that often the temperature of the clouds surrounding them was far below the freezing point, and yet ice did not form in the clouds. 4. After the War, Schaefer experimented with a machine that created cold, moist air similar to the air found in clouds. To imitate the moist air of a cloud. Schaefer would breathe into the machine. Then he would drop into the freezer a bit of powder, sugar, or some other substance. For weeks and months he tried everything he could imagine. Nothing happened. No crystals of ice were formed. None of the substances would serve as the center of a snow crystal or raindrops. 5. One July morning, Schaefer was dropping in bits of various substances and watching the unsuccessful results. Finally, a friend suggested that they go to eat lunch and Schaefer went with him. As usual, he left the cover of the freezer up, since cold air sinks and would not escape from the box. 6. Returning from lunch, Schaefer found that the temperature of the freezer had risen to a point higher than that required for ice crystals to remain solid. There were two choices now. He could close the cover and wait for the freezer itself to lower the air temperature, or he could make the process occur faster by adding dry ice a gas in solid form that is very, very cold. He chose the latter plan. As he dropped the steaming white dry ice into the freezer, he happened to breathe out a large amount of air. And there, before his eyes, it happened! He had made ice crystals, not by adding centers to the moisture, but by cooling the breath so much that the liquid had to form crystals! Then he began to blow his breath into the freezer and drop large pieces of dry ice through it to create crystals which became a tiny snowstorm falling slowly to the floor of his laboratory. 7. After planning carefully, Schaefer made an experiment by dropping dry ice from his plane to the clouds below him. As was expected, snow formed and fell from the bottom of the cloud. Schaefer succeeded. He made history.

填空题Optimists Really Do Live Longer, Say Scientists 1. For the philosopher Arthur Schopenhauer optimism was fundamentally wrong, banal and corrupting, while the father of psychoanalysis Sigmund Freund simply declared it to be neurotic. 2. Experience shows that looking on the bright side of life does have advantages and recent scientific evidence points to the positive mindset as being beneficial to health. In other words optimists live longer. 3. That was the conclusion reached by experts at the Mayo Clinic in the U.S. State of Minnesota who evaluated answers given by people to a set of questions in the 1960s. Of the 729 candidates, 200 had died and according to scientists, there were a disproportionate number of pessimists among them. 4. Ten points more on the pessimism scale—that was the difference between "slightly pessimistic" and "averagely pessimistic"—were enough to boost a person"s chances of dying by 19 percent, according to the study by prominent psychologist Martin Seligman of the University of Pennsylvania. 5. The study does not say why pessimists die but an older survey taken among children in San Francisco and Los Angeles makes it clear that personal attitude towards the world is a key factor in the longevity equation. 6. The latest evidence to support the theory that optimists tend to cope better with illness of all kinds has been provided by Professor Ralf Schwarzer of Berlin"s Free University who questioned 600 heart and lung patients. His conclusion: Optimists recover more swiftly from operations than their pessimistic counterparts; tend to be happier after treatment and return to work more swiftly. 7. There have been suggestions that optimists do not stay healthier but rather turn into optimists later because they enjoy good health. Numerous surveys have taken into account a person"s state of health at the outset and the effect remains the same. 8. Studies have shown that optimists do not blind themselves to reality either. They thus interpret it in a positive way. "Sublimating and denying things tend to alter reality but illusions are a way of seeing reality in the best light." said Californian psychology professor Shelley Taylor. 9. German science journal "Bild der Wissenschaft", which carries a major article on the topic in its current March issue, commented on "the fight attitude" to having a tumor. 10. It seems psychotherapy can go some way towards extending the life span and life quality of a sick person although a complete recovery using psychological technique alone is unlikely. 11. Doctors like, however, to point to the example of U.S. cycling professional Lance Armstrong, who was seriously ill with cancer, but whose unshakable optimism helped him to take the top trophy twice at cycling"s premier Tour de France. 12. The magazine also quoted a study by Sheldon Cohens of the Carnegie-Mellon-University in Pittsburgh: 420 volunteers were deliberately infected with strains of various common cold viruses. A day later checks were carried out to see who had caught a cold. 13. The results showed that in the case of people who had satisfactory, long-term relations with friend neighbors or colleagues, the virus was less likely to trigger a cold. Of people with three or fewer firm relationships 62 percent became ill compared with only 35 percent of those who had six or more close human links.

填空题Hurricanes (飓风) Did you know that before 1950, hurricanes had no names? They were simply given numbers. The first names were simply Alpha, Bravo, Charlie, etc. But in 1953, female names were given because of the unpredictability (不可预知) factor of the storms. In 1979, realizing the sexist (性别歧视的) nature of such names, the lists were expanded to include both men and women. Hurricanes and typhoons (台风) are the same things. If they form in the Atlantic, we call these strong storms hurricanes, from the West Indian word hurricane, meaning "big wind". And if they are Pacific storms, they are called typhoons from the Chinese taifun, meaning "great wind". To be classified as a hurricane, the storm must have maximum winds of at least 75 mph. These storms are big, many hundreds of miles in diameter. Hurricanes get their power from water vapor as it gets out its stored up energy. All water vapor gives out heat as it condenses (凝结) from a gaseous state to a liquid state over fixed points on the equator (赤道). To make a hurricane, you must have extremely wet, warm all the kind of air that can only be found in tropical regions. Scientists have determined that the heat given out in the process of water condensation can be as high as 95 billion kilowatts per hour. In just one day alone, the storm can produce more energy than many industrialized nations need in an entire year. The problem is that we don"t know how to make such great energy work for us. Predicting the path of a hurricane is one of the most difficult tasks for forecasters. It moves at a typical speed of 15 mph. But not always. Some storms may race along at twice this speed, then suddenly stop and remain in the same location in the ocean for several days. It can be maddening (发疯的) if you live in a coastal area that may be hit. The biggest advance in early detection is continuous watch from weather satellites. With these, we can see the storms form and track them fully, from birth to death. While they can still kill people and destroy property, hurricanes will never surprise any nation again.