单选题{{B}}第二篇{{/B}} {{B}} Supermarket{{/B}} Most supermarkets need a very large floor area, sometimes at least ten times as big as that of an ordinary shop. There are usually two doors, one as an entrance and the other as an exit. The rest of the side facing the street is largely of plate glass, with goods or advertising material displayed. The other three walls are normally decorated in light colours, giving an impression of cleanliness (清洁)and brightness. Most supermarkets are on one floor only. Goods being stored in rooms at the back or upstairs. At right-angles to the window stretch long structures about six feet high with a number of shelves on each side. Similar shelf units or frozen food containers extend round the wails. Broad aisles(通道)between the shelf units and ample (足够的)space between them and the window and also the far wall allow room for the circulation of many people; Individual commodities (商品), in tins, bags, boxes or other containers, are stacked (堆放) in groups on the shelves, and each group is labelled with a price ticket. Metal baskets near the entrance are taken by the shoppers who collect in them the goods they select from the shelves. Between the shelf units and the window in one half of the shops are a number of small counters about three feet high. Beside each sits a cashier (现金黄色出纳员), who operates a machine for reckoning, detailing the cost of each customer's purchases. The customer places the basket at one end of the counter so that it can be emptied by the cashier who records the price of the commodities one by one, before putting each on a moving section of the counter top. The goods are collected and packed into the customer's bag by another assistant at the end of the counter. The cashier finally hands a printed slip recording all prices to the customer, who pays the total, collects the bag and leaves.

单选题He talks tough but has a Utender/U heart.

单选题The once barren hillsides are now good farmland.

单选题Older Volcanic Eruptions Volcanoes were more destructive in ancient history, not because they were bigger, but because the carbon dioxide(二氧化碳) they released wiped out life with greater ease. Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions. Not all volcanic eruptions killed off large numbers of animals, but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock. To his surprise, the older the massive volcanic eruptions were, the more damage they seemed to do. He calculated the "killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava (熔岩) that they produced. He found that size for size, older eruptions were at least 10 times as effective at wiping out life as their more recent rivals. The Permian (二叠纪) extinction, for example, which happened 250 million years ago, is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe. Those volcanoes are thought to have pumped out about 10 gigatonnes (十亿吨) of carbon as carbon dioxide. The global warming that followed wiped out 80 percent of all marine genera (种类) at the time, and it took 5 million years for the planet to recover. Yet 60 million years ago, there was another huge amount of volcanic activity and global warming but no mass extinction. Some animals did disappear but things returned to normal within tens of thousands of years. "The most recent ones hardly have an effect at all," Wignall says. He ignored the extinction which wiped out the dinosaurs (恐龙) 65 million years ago, because many scientists believe it was primarily caused by the impact of an asteroid (小行星). He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO 2 . Vincent Courtillot, director of the Paris Geophysical Institute in France, says that Wignall"s idea is provocative. But he says it is incredibly hard to do these sorts of calculations. He points out that the killing power of volcanic eruptions depends on how long they lasted. And it is impossible to tell whether the huge blasts lasted for thousands or millions of years. He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced, and that lava volume may not necessarily correspond to carbon dioxide emissions.

单选题It is no use Udebating/U the relative merits of this policy.

单选题Sharks Perform a Service for Earth"s Waters It is hard to get people to think of sharks as anything but a deadly enemy. They are thought to 1 people frequently. But these fish perform a 2 service for earth"s waters and for human beings. Yet business and sport fishing are threatening their 3 . Some sharks are at 4 of disappearing from earth. Warm weather may influence both fish and shark activity. Many fish swim near coastal areas 5 their warm waters. Experts say sharks may follow the fish into the same areas, 6 people also swim. In fact, most sharks do not purposely charge at or bite humans. They are thought to mistake a person 7 a sea animal, such as a seal or sea lion. That is why people should not swim in the ocean when the sun goes down or comes up. Those are the 8 when sharks are looking for food. Experts also say that bright colors and shiny jewelry may cause sharks to attack. A shark has an extremely good sense of smell. It can find small amounts of substances in water, such as blood, body liquids and 9 produced by animals. These powerful 10 help sharks find their food. Sharks eat fish, any 11 sharks, and plants that live in the ocean. Medical researchers want to learn more about the shark"s body defense and immune systems 12 disease. Researchers know that sharks 13 quickly from injuries. They study the shark in hopes of finding a way to fight human disease. Sharks are important for the world"s 14 . They eat injured and diseased fish. Their hunting activities mean that the numbers of other fish in ocean waters do not become too 15 . This protects the plants and other forms of life that exist in the oceans.

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.