全国大学英语四级考试试题Word格式.docx

1、For questions 1-7, markY （for YES） if the statement agrees with the information given in the passage;N （for NO） if the statement contradicts the information given in the passage;NG （for NOT GIVEN） if the information is not given in the passage。For questions 8-10, complete the sentences with the info

2、rmation given in the passage。 Will We Run Out of Water?Picture a “ghost ship” sinking into the sand, left to rot on dry land by a receding sea. Then imagine dust storms sweeping up toxic pesticides and chemical fertilizers from the dry seabed and spewing them across towns and villages。Seem like a sc

3、ene from a movie about the end of the world? For people living near the Aral Sea in Central Asia, its all too real. Thirty years ago, government planners diverted the rivers that flow into the sea in order to irrigate（provide water for）farmland. As a result, the sea has shrunk to half its original s

4、ize, stranding ships on dry land. The seawater has tripled in salt content and become polluted, killing all 24 native species of fish。Similar large-scale efforts to redirect water in other parts of the world have also ended in ecological crisis, according to numerous environmental groups. But many c

5、ountries continue to build massive dams and irrigation systems, even though such projects can create more problems than they fix. Why? People in many parts of the world are desperate for water, and more people will need more water in the next century。“Growing populations will worsen problems with wa

6、ter,” says Peter H. Gleick, an environmental scientist at the Pacific Institute for studies in Development, Environment, and Security, a research organization in California. He fears that by the year 2025, as many as one third of the worlds projected 8.3 billion people will suffer from water shortag

7、es。Where Water GoesOnly 2.5 percent of all water on Earth is freshwater, water suitable for drinking and growing food, says Sandra Postel, director of the Global Water Policy Project in Amherst, Mass. Two thirds of this freshwater is locked in glaciers and ice caps. In fact, only a tiny percentage o

8、f freshwater is part of the water cycle, in which water evaporates and rises into the atmosphere, then condenses and falls back to Earth as precipitation（rain or snow）。Some precipitation runs off land to lakes and oceans, and some becomes groundwater, water that seeps into the earth. Much of this re

9、newable freshwater ends up in remote places like the Amazon river basin in Brazil, where few people live. In fact, the worlds population has access to only 12,500 cubic kilometers of freshwaterabout the amount of water in Lake Superior. And people use half of this amount already. “If water demand co

10、ntinues to climb rapidly,” says Postel, “there will be severe shortages and damage to the aquatic environment。”Close to HomeWater woes may seem remote to people living in rich countries like the United States. But Americans could face serious water shortages, too especially in areas that rely on gro

11、undwater. Groundwater accumulates in aquifers, layers of sand and gravel that lie between soil and bedrock. （For every liter of surface water, more than 90 liters are hidden underground。）Although the United States has large aquifers, farmers, ranchers, and cities are tapping many of them for water f

12、aster than nature can replenish it. In northwest Texas, for example, over pumping has shrunk groundwater supplies by 25 percent, according to Postel。Americans may face even more urgent problems from pollution. Drinking water in the United States is generally safe and meets high standards. Neverthele

13、ss, one in five Americans every day unknowingly drinks tap water contaminated with bacteria and chemical wastes, according to the Environmental Protection Agency. In Milwaukee, 400,000 people fell ill in 1993 after drinking tap water tainted with cryptosporidium, a microbe that causes fever, diarrhe

14、a and vomiting。The SourceWhere do contaminants come from? In developing countries, people dump raw sewage into the same streams and rivers from which they draw water for drinking and cooking; about 250 million people a year get sick from water borne diseases。In developed countries, manufacturers use

15、 100,000 chemical compounds to make a wide range of products. Toxic chemicals pollute water when released untreated into rivers and lakes. （Certain compounds, such as polychlorinated biphenyls, or PCBs, have been banned in the United States。）But almost everyone contributes to water pollution. People

16、 often pour household cleaners, car antifreeze, and paint thinners down the drain; all of these contain hazardous chemicals. Scientists studying water in the San Francisco Bay reported in 1996 that 70 percent of the pollutants could be traced to household waste。Farmers have been criticized for overu

17、sing herbicides and pesticides, chemicals that kill weeds and insects but that pollute water as well. Farmers also use nitrates, nitrogen-rich fertilizer that help plants grow but that can wreak havoc on the environment. Nitrates are swept away by surface runoff to lakes and seas. Too many nitrates

18、“over enrich” these bodies of water, encouraging the buildup of algae, or microscopic plants that live on the surface of the water. Algae deprive the water of oxygen that fish need to survive, at times choking off life in an entire body of water。Whats the Solution?Water expert Gleick advocates conse

19、rvation and local solutions to water-related problems; governments, for instance, would be better off building small-scale dams rather than huge and disruptive projects like the one that ruined the Aral Sea。“More than 1 billion people worldwide dont have access to basic clean drinking water,” says G

20、leick。“There has to be a strong push on the part of everyonegovernments and ordinary peopleto make sure we have a resource so fundamental to life。1. That the huge water projects have diverted the rivers causes the Aral Sea to shrink。2. The construction of massive dams and irrigation projects does mo

21、re good than harm。3. The chief causes of water shortage are population growth and water pollution。4. The problems Americans face concerning water are groundwater shrinkage and tap water pollution。5. According to the passage all water pollutants come from household waste。6. The people living in the U

22、nited States will not be faced with water shortages。7. Water expert Gleick has come up with the best solution to water-related problems。1.YNNG2.YNNG3.YNNG4.YNNG5.YNNG6.YNNG7.YNNG8. According to Peter H. Gleick, by the year 2025, as many as of the worlds people will suffer from water shortages。9.Two

23、thirds of the freshwater on Earth is locked in。10.In developed countries, before toxic chemicals are released into rivers and lakes, they should be treated in order to avoid。Part III Listening Comprehension （35 minutes）Section A In this section, you will hear 8 short conversations and 2 long convers

24、ations. At the end of each conversation, one or more questions will be asked about what was said. Both the conversation and the questions will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices marked A,B,CandD, and decide which is the be

25、st answer. Then mark the corresponding letter on Answer Sheet 2 with a single line through the centre。11.AWait for the sale to start。BGet further information about the sale。CCall the TV station to be sure if the ad is true。DBuy a new suit。12.AHe doesnt think that John is ill。BHe thinks that perhaps

26、John is not in very good health。CHe is aware that John is ill。DHe doesnt think that John has a very good knowledge of physics。13.ABefore six。BAt six。CAfter six。DAfter seven。14.AIt is bigger。BIt has a prettier color。CIt has a larger yard。DIt is brighter。15.AAustralian and American。BGuest and host。CHu

27、sband and wife。DProfessor and student。16.A130.B1100.C930.D1000.17.AHe prefers staying at home because the bus is too late。BHe prefers staying at home because he doesnt like to travel。CHe prefers taking a bus because the plane makes him nervous。DHe prefers traveling with the woman。18.AHe thinks she s

28、hould visit her cousin。BHer cousin doesnt visit very often。CHer cousin is feeling a lot better today。DHe doesnt think her cousin has been at home today。Questions 19 to 22 are based on the conversation you have just heard。19.ATwo different types of bones in the human body。BHow bones help the body mov

29、e。CHow bones continuously repair themselves。DThe chemical composition of human bones。20.AThey defend the bone against viruses。BThey prevent oxygen from entering the bone。CThey break down bone tissue。DThey connect the bone to muscle tissue。21.AThey have difficulty identifying these cells。BThey arent sure how these cells work。CTheyve learned how to reproduce these cells。DTheyve found similar cells in other species。22.ATo learn how to prevent a bone disease。BTo understand differences between bone tissue and other tissue。