单选题His friend unexpectedly dropped in.

单选题Last year, our company sold twice as many computers as our competitor.A. rivalB. enemyC. partnerD. co-worker

单选题Ancient Egypt Brought down by Famine Even ancient Egypt's mighty pyramid (金字塔) builders were powerless in the face of the famine (饥荒)that helped bring down their civilization around 2180 B．C.. Now evidence collected from mud deposited by the River Nile suggests that a shift in climate thousands of kilometers to the south was ultimately to blame and the same or worse could happen today. The ancient Egyptians depended on the Nile's annual floods to irrigate their crops. But any change in climate that pushed the African monsoons (季风) southwards out of Ethiopia would have reduced these floods. Declining rains in the Ethiopian highlands would have meant fewer plants to stabilize the soil. When rain did fall it would have washed large amounts of soil into the Blue Nile and into Egypt, along with sediment (沉积) from the White Nile. Blue Nile mud has a different isotope (同位素) signature from that of the white Nile, so by analyzing isotope differences in mud deposited in the Nile Delta Michael Krom of Leeds University worked out what proportion of sediment came from each branch of the river. Krom reasons that during periods of drought, the amount of Blue Nile mud in the river would be relatively high. He found that one of these periods, from 4500 to 4200 years ago, immediately came before the fall of the Egypt's old Kingdom. The weakened waters would have been disaster for the Egyptians. " Changes that affect food supply don't have to be very large to have a ripple (波浪) effect in societies. " says Bill Ryan of the Lamont Doherty Earth Observatory in New York. "Similar events today could be even more devastating," says team member Daniel Stanley, a scientist from the Smithsonian Institution in Washington D.C.. "Anything humans do to shift the climate belts would have an even worse effect along the Nile system today because the populations have increased dramatically. /

单选题Computers The initial impact of computers was in the area of entertainment. If you walked by a video arcade in the early 1980s, you could not have failed to notice that the use of video games was growing at what some considered an alarming rate. In 1981 the movie industry grossed $ 3 billion, video games took in an estimated $ 6 billion. That gives you some idea of just how big the computer industry had become. Video games employ the same technology as personal computers, and indeed many who bought personal computers did so primarily for playing games at home, thus saving their quarters. Though video games are not as popular as they were a few years age, they did provide consumer with their first real reason to buy PCs. A. more recent computer innovation, desktop publishing, supplies one good reason for those who write for a living to buy a PC. Desktop publishing is a deceptively simple description for an extremely complex group of hardware and software tools. You can now write text, edit text, draw illustrations, incorporate photographs, design page layouts, and print a finished document with a relatively inexpensive computer and laser printer. Although the new technology offers new freedom, there is a price to be paid for this freedom. With total control comes total responsibility. In fact, the issue of social responsibility in our new computer age has long been a topic of debate among computer enthusiasts. Some people are concerned with the long-term social effects of the so-called computer revolution. Ironically, many PC. pioneers who built and marketed the first machines were 60s-style advocates of social change. They claim that while personal computer technology has the potential to make society more equal, it's having the opposite effect since upper-middle-class people can afford them and lower-class people cannot. In addition, the ways that computers are used to monitor the activities of their users have evoked anxiety about the machine. Over 7 million Americans now have their work paced, controlled, and monitored by computers. A. computer is more restrictive and powerful in the way it controls people than the old-fashioned assembly line. This can lead to what some have called "tech-stress". Irritated eyes, back problems, and other physical symptoms have also been associated with the extensive use of computers. Although the personal computer may not have had the impact some predicted a decade age, the combination of computer technology with satellites and cable does promise innovations in the mass media that would have seemed astonishing just a few short years ago.

单选题Radios are not permitted in the library. ______

单选题Hitchhiking (搭车旅游) When I was in my teens (十几岁) and 20s, hitchhiking was a main form of long-distance transport. The kindness or curiosity of strangers (1) me all over Europe, North America, Asia and southern Africa. Some of the lift-givers became friends, many provided hospitality (2) the road. Not only did you find out much more about a country than (3) traveling by train or plane, but also there was that element of excitement about where you would finish up that night. Hitchhiking featured importantly in Western culture. It has books and songs about it. So what has happened to (4) ? A few years ago, I asked the same question about hitchhiking in a column on a newspaper. (5) of people from all over the world responded with their view on the state of hitchhiking. "If there is a hitchhiker's (6) it must be Iran," came one reply. Rural Ireland was recommended as a friendly place for hitchhiking, (7) was Quebec, Canada-"if you don't mind being berated (严厉指责) for not speaking French. But while hitchhiking was clearly still alive and well in many parts of the world, the (8) feeling was that throughout much of the west it was doomed (消亡). With so much news about crime in the media, people assumed that anyone on the open road without the money for even a bus ticket must present a danger. But do we (9) to be so wary both to hitchhike and to give a lift? In Poland in the 1960s, (10) a Polish woman who e-mailed me, "the authorities introduced the Hitchhiker's Booklet. The booklet contained coupons for drivers, so each time a driver (11) somebody, he or she received a coupon. At the end of the season, (12) who had picked up the most hikers were rewarded with various prizes. Everybody was hitchhiking then. " Surely this is a good idea for society. Hitchhiking would increase respect by breaking down (13) between strangers. It would help fight (14) warming by cutting down on fuel consumption as hitchhikers would be using existing fuels. It would also improve educational standards by delivering instant (15) in geography, history, politics and sociology.

单选题These are the motives for doing it.

单选题Paragraph 5_____

单选题Antibiotic Resistance Clue Found US scientists have uncovered a defence mechanism in bacteria that allows them to fend off the threat of antibiotics. It is hoped the findings could help researchers boost the effectiveness of existing treatments. The study published in Science found that nitric oxide produced by the bacteria eliminates some key effects of a wide range of antibiotics. One UK expert said inhibiting nitric oxide synthesis could be an important advance for tackling tricky infections. Antibiotic resistance, for example with MRSA, is a growing problem and experts have long warned of the need to develop new treatments. The latest research, done by a team at New York University, showed that in bacteria the production of nitric oxide—a small molecule made up of one nitrogen and one oxygen atom—increased their resistance to antibiotics. They found the enzymes responsible for producing nitric oxide were activated specifically in response to the presence of the antibiotics. They also showed that nitric oxide alleviates damage caused by the drugs as well as helping to neutralise many of the toxic compounds within the antibiotic. The researchers then showed that eliminating nitric oxide production in the bacteria allowed the antibiotics to work at lower, less toxic doses. More effective Study leader, Dr Evgeny Nudler, said developing new medicines to fight antibiotic resistance, such as that seen with MRSA is a" huge hurdle". "Here, we have a short cut, where we don't have to invent new antibiotics. "Instead we can enhance the activity of well - established ones, making them more effective at lower doses. Dr Matthew Dryden, consultant in microbiology and communicable disease at Royal Hampshire County Hospital and general secretary of the British Society for Antimicrobial Chemotherapy, said if the enzyme which creates nitric oxide could be inhibited, it could suppress the ability of the bacteria to counteract antibiotics. "This would be a useful therapeutic advance, especially as we are running out of new classes of antibiotics and there is less antibiotic development in general. /

单选题Moving pictures present {{U}}spectacular{{/U}} scenes like battles, processions, storms or races.

单选题 阅读下面的短文，文中有15处空白，每处空白给出4个选项。请根据短文的内容，从4个选项中选择1个最佳答案。 {{B}}British Government{{/B}} When British voters go to the polls during General Elections to decide {{U}}(51) {{/U}} will govern them they usually have a choice of at least three candidates who will each {{U}}(52) {{/U}} one of the three main political parties in Britain today. The Labour Party is the party of {{U}}(53) {{/U}}, while the Tory Conservative Party the right and {{U}}(54) {{/U}} the two, with policies and opinions of its own, is the smaller Liberal Party. Britain is divided into over 600 political units called "constituencies", each with {{U}}(55) {{/U}} own candidates who stand for Parliament hoping to be elected (or re-elected) with large majorities. The cities and large towns are themselves divided into constituencies and they also choose the Members of parliament (MPs) who will represent their {{U}}(56) {{/U}} in the houses of Parliament at Westminster. Here, in the "House", the government {{U}}(57) {{/U}} the day led by its Prime minister and his Cabinet—a team of specially selected ministers—{{U}} (58) {{/U}} its duties of governing the country. Various proposals are put forward for debate and discussion and these may, {{U}}(59) {{/U}} become part of the law of the land. The government {{U}}(60) {{/U}} has to face the criticism of the other parties which are in opposition. This. is the sort of democratic process that the majority of British people seem to {{U}}(61) {{/U}} Her Majesty's Government is watched over by Her Majesty's Opposition, and {{U}}(62) {{/U}} a certain balance of power is maintained. Decisions are made by a majority vote and this, of course, is {{U}}(63) {{/U}} the other parties, the liberals, the national and Regional parties and other independent parties can {{U}}(64) {{/U}} their influence. Some issues may be decided on a {{U}}(65) {{/U}} handful of votes.

单选题下面有3篇短文，每篇短文后有5道题，每题后面有4个选项。请仔细阅读短文并根据短文回答其后面的问题。{{B}}第一篇{{/B}} {{B}} Energy Crisis{{/B}} One key question for the next century is how we provide energy in an environmentally sound way. As living standards rise in the developing world, energy consumption will increase. As a result, many countries are now opening the door for private investment in a sector that used once to be solely the preserve of government. In the developed world, the move is towards the deregulation and privatization of electricity generation and distribution. There is also a trend towards locally-generated energy, particularly in the developing world. Factories and shopping centers may one day have their own power sources. Progress is also being made in minimizing the environmental impact of energy production and consumption. A motor car today puts out perhaps 5 percent of the pollution a new car did in 1970. We can produce clean power too but it costs, so in the new millennium(一千年) we're to some extent going to have the environment we can afford. The spectre of scarce or impossibly expensive energy is no longer with us, thanks to a combination of opening up new regions of the world and new technologies. Shortage is very unlikely. Environmental considerations mean there is a seriousness too about alternative energy sources that wasn't there ten years ago. Right now the fuel cell is at the top of the list of alternative technologies. Advances in turbine transportation mean that natural gas is going to have an ever-increasing role. Nuclear power may prove competitive enough to have a much longer life than many expect, but until there's a major change in public sentiment, I don't expect to see much new nuclear construction. Will the grip of oil on personal transportation continue? Sports utility vehicles like Land Rovers and jeeps are hardly the perfect means of urban transport. But people have become very attached to their automobiles. So until we get around to technology where we beam ourselves around, I suspect we'll continue to have them. Some may be electric; others could run on cleaner oil-based fuel or natural gas. One area which is certainly not clear is the impact of the internet on transport. On the one hand, you will be able to accomplish by sitting in front of a screen what you used to have to go to the airport for, on the otherhand, increased knowledge may well fuel a rising demand for travel. We are only at the beginning of a revolution that is already being called a bigger revolution than the internal combustion engine(内燃机).

单选题The two banks have announced plans to merge next year.

单选题Mary has blended the ingredients. A. mixed B. made C. cooked D. eaten

单选题下面的短文后列出了7个句子，请根据短文的内容对每个句子做出判断，如果该句提的是正确信息， 请选择A；如果该句提的是错误信息，请选择B；如果该句的信息句的信息文中没有提及，请选择C。 Why is the Native Language Learnt So Well How does it happen that children learn their mother tongue so well? When we compare them with adults learning a foreign language, we often find this interesting fact. A little child without knowledge or experience often succeeds in a complete mastery(精通) of the language. A grown-up person with fully developed mental powers, in most case, may end up with a faulty and inexact command(掌握). What accounts for this difference? Despite other explanations, the real answer in my opinion lies partly in the child himself, partly in the behavior of the people around him. In the first place, the time of learning the mother tongue is the most favorable of all, namely, the first years of life. A child hears it spoken from morning till night and, what is more important, always in its genuine form, with the right pronunciation, right intonation, right use of words and right structure. He drinks in(吸引) all the words and expressions, which come to him in a flash, ever-bubbling(冒泡的) spring. There is no resistance: there is perfect assimilation. Then the child has, as it were, private lessons all the year round, while an adult language-student has each week a limited number of hours, which he generally shares with others. The child has another advantage : he hears the language in all possible situations, always accompanied by the right kind of gestures and facial expressions. Here there is nothing unnatural, such as it is often found in language lessons in schools, when one talks about ice and snow in June or scorching heat in January. And what a child hears is generally what immediately interests him. Again and again, when his attempts at speech are successful, his desires are understood and fulfilled. Finally, though a child's "teachers" may not have been trained in language teaching, their relations with him are always close and personal. They take great pains to make their lessons easy.

单选题下面有3篇短文，每篇短文后有5道题，每道题后面有4个选项。{{B}}第一篇{{/B}} {{B}}Eat Healthy{{/B}} "Clean your plate!" and "Be a member of the clean-plate club!" Just about every kid in the US has heard this from a parent or grandparent. Often, it's accompanied by an appeal: "Just think about those starving orphans in Africa!" Sure, we should be grateful for every bite of food. Unfortunately, many people in the US take too many bites. Instead of staying "clean the plate", perhaps we should save some food for tomorrow. According to news reports, US restaurants are partly to blame for the growing bellies. A waiter puts a plate of food in front of each customer, with two to four times the amount recommended by the government, according to a USA Today story. Americans traditionally associate quantity with value and most restaurants try to give them that. They prefer to have customers complain about too much food rather than too little. Barbara Rolls, a nutrition professor at Pennsylvania State University, told USA Today that restaurant portion sizes began to grow in the 1970s, the same time that the American waistline began to expand. Health experts have tried to get many restaurants to serve smaller portions. Now, apparently, some customers are calling for this too. The restaurant industry trade magazine QSR reported last month that 57 percent of more than 4,000 people surveyed believe restaurants serve portions that are too large; 23 percent had no opinion; 20 percent disagreed. But a closer look at the survey indicates that many Americans who can't afford free dining still prefer large portions. Seventy percent of those earning at least $150,000 per year prefer smaller portions; but only 45 percent of those earning less than $25,000 want smaller. It's not that working class Americans don't want to eat healthy. It's just that, after long hours at low-paying jobs, getting less on their plate hardly seems like a good deal. They live from paycheck to paycheck, happy to save a little money for next year's Christmas presents.

单选题The book made a great impact on its readers.

单选题Ruth Benedict's highly popular book Patterns of Culture stressed the role of culture in personality formation.

单选题Why didn’t NASA scientists identify the problem before the Orbiter left for Mars?

单选题Global climate change was the dominant {{U}}theme{{/U}} of the conference.