单选题{{B}}第二篇{{/B}} Geologists have been studying volcanoes for a long time. Though they have learned a great deal, they still have not discovered the cause of volcanic action. They know that the inside of the earth is very hot, but they are not sure exactly what causes the great heat. Some geologists have thought that the heat is caused by the great pressure of the earth's outer layers. Or the heat may be left from the time when the earth was formed. During the last sixty years scientists have learned about radium, uranium, thorium, and other radioactive elements. These give out heat all the time as they change into other elements. Many scientists now believe that much of the heat inside the earth is produced by radioactive elements. Whatever the cause of the heat may be, we do know that the earth gets hotter the farther down we dig. In deep mines and oil wells the temperature rises about 1 F for each 50 feet. At this rate the temperature 40 miles below the earth' s surface would be over 4,000 F, This is much hotter than necessary to melt rock. However, the pressure of the rock above keeps most materials from melting at their usual melting points. Geologists believe that the rock deep in the earth may be plastic, or puttylike. In other words, the rock yields slowly to pressure but is not liquid. But if some change in the earth's crust releases the pressure, the rock melts. Then the hot, liquid rock can move up toward the surface. When the melted rock works its way close to earth's crust, a volcano may be formed. The melted rock often contains steam and other gases under great pressure. If the rock above gives way, the pressure is released. Then the sudden expansion of the gases causes explosions. Theses blow the melted rock into pieces of different sizes and shoot them high in the air. Here they cool and harden into volcanic ash and cinders. Some of the material falls around the hole made in the earth's surface. The melted rock may keep on rising and pour out as lava. In this way, volcanic ash, cinders and lava build up the cone-shaped mountains that we call volcanoes.

单选题In the dark night of the desert, a group of US Air Force scientists is testing a new device for a missile to target. Designed to seek out the heat of an enemy aircraft engine, it is now going through its paces by tracing the movement of a flashlight waving thirty feet away in the darkness. A hundred yards away, unseen by the man, a rattlesnake sliding between the stones senses a patch of warmth. Although the snake's mechanism is small enough to be packed into a head the size of a nut, it can detect a change in temperature of one-thousandth of a degree. With a sound the snake closes in and strikes for the kill. Whenever we look in the animal world we find the same story. Almost anything that man can do, nature has already done better. So, it is for the purpose of learning from nature that a new science called bionics has grown up. Its aim is to find out how animal's instruments work so that man can copy them for his own purpose. Imagine being able to know a friend several miles off by his smell. Male silk moths can do this. Their antennae are so sensitive to the chemical odor of female moths that they can detect their presence by picking up only one molecule of the chemical. Even with their most sensitive instruments, human cannot approach this perfection. Studying beetle's eyes has already paid off. A group of scientists in Germany found that a beetle can accurately measure with its eyes the speed of moving background. After finding out how a beetle accomplishes this scientists built a machine that operated on the same principle. This instrument is able to determine the ground speed of moving aircraft with a high degree of accuracy.

单选题The council meeting terminated at 2 o’clock.

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：如果该句提供的是正确信息，请选择A；如果该句提供的是错误信息，请选择B；如果该句的信息文中没有提及，请选择C。 A Great Quake Coming? Everyone who lives in San Francisco knows that earthquakes are common in the Bay Area-and they can be devastating．In 1906，for example，a major quake destroyed about 28,000 buildings and killed hundreds，perhaps thousands of people．Residents now wonder when the next“Big One”will strike．It's bound to happen someday．At least seven active fault(断层)lines run through the San Francisco area． Faults are places where pieces of Earth's crust(地壳)slide past each other．When these pieces slip，the ground shakes． To prepare for that day，scientists are using new techniques to reanalyze the 1906 earthquake and predict how bad the damage might be when the next one happens． One new finding about the 1906 quake is that the San Andreas Fault split apart faster than scientists had assumed at the time．During small earthquakes，faults rupture(断裂)at about 2.7 kilometers per second．During bigger quakes，however，ruptures can happen at rates faster than 3.5 kilometers per second． At such high speeds，massive amounts of pressure build up，generating underground waves that can cause more damage than the quake itself．Lucky for San Francisco，these pressure pulses(脉冲)traveled away from the city during the 1906 event．As bad as the damage was，it could have been far worse． Looking ahead，scientists are trying to predict when the next major quake will occur．Records show that earthquakes were common before 1906．Since then，the area has been relatively quiet．Patterns in the data，however，suggest that the probability of a major earthquake striking the Bay Area before 2032 is at least 62 percent． New buildings in San Francisco are quite safe in case of future quakes．Still，more than 84 percent of the city's buildings are old and weak．Analyses suggest that another massive earthquake would cause extensive damage． People who live there today tend to feel safe because San Francisco has remained pretty quiet for a while．According to the new research，however，it's not a matter of“if”the Big One will hit．It's just a matter of when．

单选题The fuel tanks had a capacity of 140 liters.

单选题Experts Call for Local and Regional Control of Sites for Radioactive Waste The withdrawal of Nevada's Yucca Mountain as a potential nuclear waste repository has reopened the debate over how and where to dispose of spent nuclear fuel and high-level nuclear waste. In an article in the July 10 issue of Science, University of Michigan geologist Rodney Ewing and Princeton University nuclear physicist Frank von Hippel argue that, although federal agencies should set standards and issue licenses for the approval of nuclear facilities, local communities and states should have the final approval on the sitting of these facilities. The authors propose the development of multiple sites that would service the regions where nuclear reactors are located. "The main goal..., should be to provide the United States with multiple process that requires acceptance by host communities and states," the authors write. Ewing and yon Hippel also analyze the reasons why Yucca Mountain, selected by Congress in 1987 as the only site to be investigated for long-term nuclear waste disposal, finally was shelved after more than three decades of often controversial debate. The reasons include the site's geological problems, management problems, important changes in the Environmental Protection Agency's standard, unreliable funding and the failure to involve local communities in the decision-making process. Going forward, efforts should be directed at locating storage facilities in the nation's northeastern, southeastern, mid-western and western regions, and states within a given region should be responsible for developing solutions that suit their particular circumstances. Transportation of nuclear waste over long distances, which was a concern with the Yucca Mountain site, would be less of a problem because temporary storage or geological disposal sites could be located closer to reactors. "This regional approach would be similar to the current approach in Europe, where spent nuclear fuel and high-level nuclear waste from about 150 reactors and reprocessing plants is to be moved to a number of geological repositories in a variety of rock types," said Rodney Ewing, who has written extensively about the impact of nuclear waste management on the environment and who has analyzed safety assessment criteria for the controversial Yucca Mountain nuclear waste repository.

单选题Grasses and flowers in the desert whose life cycles are short shows their ability to adapt to the quick disappearance of rainwater there after it falls in spring.

单选题He still did well at school ______ takeing a part-time jobs now and then.A. in spite ofB. regardingC. on account ofD. in case of

单选题The earthquake that hit the eastern half of the United States two centuries ago is the biggest “mid-plate” one in history.

单选题A plastic wheel can be as {{U}}tough{{/U}} as a metal one. A. useful B. tight C. weak D. strong

单选题The result was a sensational 4:1 victory.

单选题Hearing problems may be alleviated by changes in diet and exercise habits.

单选题Molly Brown was labeled “unsinkable” after she helped to {{U}}evacuate{{/U}} passengers from the ill-fated ship the Titanic.

单选题The Science of the Future Until recently, the "science of the future" was supposed to be electronics and artificial intelligence. Today it seems more and more likely that the next great breakthroughs in technology will be brought through a combination of those two sciences with organic chemistry and genetic engineering. This combination is the science of biotechnology. Organic chemistry enables us to produce marvelous synthetic (合成的) materials. However, it is still difficult to manufacture anything that has the capacity of wool to conserve heat and also to absorb moisture. Nothing that we have been able to produce so far comes anywhere near the combination of strength, lightness and flexibility that we find in the bodies of ordinary insects. Nevertheless, scientists in the laboratory have already succeeded in "growing" a material that has many of the characteristics of human skin. The next step may well be "biotech hearts and eyes" which can replace diseased organs in human beings. These will not be rejected by the body, as is the case with organs from humans. The application of biotechnology to energy production seems even more promising. In 1996 the famous science-fiction writer, Arthur C. Clarke, many of whose previous predictions have come true, said that we may soon be able to develop remarkably cheap and renewable sources of energy. Some of these power sources will be biological. Clarke and others have warned us repeatedly that sooner or later we will have to give up our dependence on non-renewable power sources. Coal, oil and gas are indeed convenient. However, using them also means creating dangerously high levels of pollution. It will be impossible to meet the growing demand for energy without increasing that pollution to catastrophic (灾难性的) levels unless we develop power sources that are both cheaper and cleaner. It is attempting to think that biotechnology or some other "science of the future" can solve our problems. Before we surrender to that temptation we should remember nuclear power. Only a few generations ago it seemed to promise limitless, cheap and safe energy. Today those promises lie buried in a concrete grave in a place called Chernobyl, in the Ukraine. Biotechnology is unlikely, however, to break its promises in quite the same or such a dangerous way.

单选题 Racial Prejudice In some countries where racial prejudice is acute, violence has been taken for granted as a means of solving differences; and this is not even questioned. There are countries {{U}} {{U}} 1 {{/U}} {{/U}}the white man imposes his rude by brute (粗暴) force; there are countries where the black man protests by {{U}} {{U}} 2 {{/U}} {{/U}}fire to cities and by looting and pillaging (抢夺). Important people on both sides, who would in other respects appear to be reasonable men, get up and calmly argue in {{U}} {{U}} 3 {{/U}} {{/U}}of violence as if it were a legitimate (合法的) solution, {{U}} {{U}} 4 {{/U}} {{/U}}any other. What is really frightening, what really {{U}} {{U}} 5 {{/U}} {{/U}}you with despair, is the realization that when it comes to the crunch (关键时刻), we have made no actual {{U}} {{U}} 6 {{/U}} {{/U}}at all. We may wear collars and ties instead of war paint, but our instincts remain basically unchanged. The whole of the recorded {{U}} {{U}} 7 {{/U}} {{/U}}of the human race, that tedious documentation of violence, has taught us absolutely nothing. We have still not learnt that {{U}} {{U}} 8 {{/U}} {{/U}}never solves a problem but makes it more acute. The sheer horror, the bloodshed and the suffering {{U}} {{U}} 9 {{/U}} {{/U}}nothing. No solution ever comes to {{U}} {{U}} 10 {{/U}} {{/U}}the morning after when we dismally (阴郁地) contemplate the smoking ruins and wonder what hit us. The truly reasonable men who {{U}} {{U}} 11 {{/U}} {{/U}}where the solutions lie are finding it harder and harder to get a hearing. They are despised, mistrusted and even persecuted {{U}} {{U}} 12 {{/U}} {{/U}}their own kind because they advocate such apparently outrageous things as low enforcement. If half the energy that goes into {{U}} {{U}} 13 {{/U}} {{/U}}acts were put to good use, if our efforts were directed at {{U}} {{U}} 14 {{/U}} {{/U}}up the slums and ghettos (贫民窟), at improving living standards and providing education and employment for all, we would not have gone a long way to {{U}} {{U}} 15 {{/U}} {{/U}}at a solution.

单选题People in the little town lived a life of ease .

单选题When Jack eventually overtook the last truck he pulled over to the inside lane.A. skippedB. passedC. reachedD. led

单选题TV Games Shows One of the most fascinating things about television is the size of the audience. A novel can be on the "best sellers" list with a sale of fewer than 100,000 copies, but a popular TV show might have 70 million TV viewers. TV can make anything or anyone well known overnight. This is the principle behind "quiz" or "game" shows, which put ordinary people On TV to play a game for the prize and money. A quiz show can make anyone a star, and it can give away thousands of dollars just for fun. But all of this money can create problems. For instance, in the 1950s, quiz shows were very popular in the U. S. and almost everyone watched them. Charles Van Doren, an English instructor, became rich and famous after winning money on several shows. He even had a career as a television personality. But one of the losers proved that Charles Van Doren was cheating. It turned out that the show"s producers, who were pulling the strings, gave the answers to the most popular contestants beforehand. Why? Because if the audience didn"t like the person who won the game, they turned the show off. Based on his story, a movie under the title "Quiz Show" is on 40 years later. Charles Van Doren is no longer involved with TV. But game shows are still here, though they aren"t taken as seriously. In fact, some of them try to be as ridiculous as possible. There are shows that send strangers on vacation trips together, or that try to cause newly married couples to fight on TV, or that punish losers by humiliating them. The entertainment now is to see what people will do just to be on TV. People still win money, but the real prize is to be in front of an audience of millions.

单选题It is said the houses aidng this street will soon be {{U}}demolishe{{/U}}