1、大学英语四级改革适用（阅读）模拟试卷 283 及答案解析(总分：60.00，做题时间：90 分钟)一、Reading Comprehensio(总题数：6，分数：60.00)1.Part III Reading Comprehension（分数：10.00）_2.Section C（分数：10.00）_If the salinity (含盐量) of ocean waters is analyzed, it is found to vary only slightly from place to place. Nevertheless, some of these small changes
2、are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporationconversion of liquid water to water vapor. In this manner, the salinity is increased, since the salts stay behind. If this is carried
3、 to the extreme, of course, white crystals of salt would be left behind. The opposite of evaporation is precipitation (降水), such as rain, by which water is added to the ocean. Here the ocean is being diluted(稀释) so that the salinity is decreased. This may occur in areas of high rainfall or in coasta
4、l regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation or runoff (形成地表水部分的降雨). Normally, in tropical regions where the sun is very strong, the ocean salinity is somewhat highe
5、r than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas. A third process by which salinity may be altered is associated with the formation and melting of sea ice
6、 When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly beneath freshly-formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water. In the Wedde
7、ll Sea, off Antarctica, the densest water in the oceans is. formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portions of the oceans of the world.（分数：10.00）(1).The best title of the passage can be “_“.（分数：2.00）A
8、Typical Oceans and Their Respective FeaturesB.The Causes of the Changes in Salinity of Ocean WaterC.Different Oceans Have Different SalinityD.The Precipitation and Evaporation of Oceans(2).Which of the following processes will increase salinity of ocean waters?（分数：2.00）A.Evaporation.B.Precipitation
9、C.Melting.D.Dilution.(3).According to this passage, the sea _ is likely to have the lowest salinity.（分数：2.00）A.in tropical areasB.off AntarcticaC.of high rainfallD.with abundant sunshine(4).The Weddell Sea_.（分数：2.00）A.is a good example of increased salinity in freezing sea waterB.is much larger in
10、area than the Arctic oceansC.has a much lower salinity now than everD.has the denser water in its upper parts(5).Coastal regions are mentioned as cases where _.（分数：2.00）A.sea water is less salty because fresh water joins inB.rivers carry industrial exhaust into seaC.sea ice tends to melt more quickl
11、y than in the center of oceansD.heavy water sinks to the deeper portions of the oceansAlthough many of us may feel air-conditioners bring relief from hot, humid or polluted outside air, they pose many potential health hazards. Much research has looked at how the movement of air inside a closed envir
12、onmentsuch as an office buildingcan spread disease or expose people in the building to harmful chemicals. One of the more widely publicized dangers is that of Legionnaires disease, which was first recognized in the 1970s. This was found to have affected people in buildings with air-conditioning syst
13、ems in which warm air pumped out of the systems cooling towers was somehow sucked back into the air intake (通风口), in most cases due to poor design. The warm air, filled with bacteria, was combined with cooled, conditioned air and was then circulated around various parts of the building. Studies show
14、ed that even people outside such buildings were at risk if they walked past air exhaust pipes. Large air-conditioning systems add water to the air they circulate by means of humidifiers (湿度调节器 ). In older systems, the water used for this process is kept in special reservoirs, the bottoms of which pr
15、ovide breeding grounds for bacteria which can find their way into the ventilation (通风) system. The risk to human health from this situation has been highlighted by the fact that the immune systems (免疫系统) of approximately half of workers in air-conditioned office buildings have developed the ability
16、to fight off the organisms found at the bottom of system reservoirs. But chemicals called “biocides“ are added to reservoirs to make them germ-free, and they are dangerous in their own right in sufficient quantities, as they often contain compounds strongly linked to cancers. Finally, it should be p
17、ointed out that the artificial climatic environment created by air-conditioners can also affect us. In a natural environment, whether indoor or outdoor, there are small variations in temperature and humidity. Indeed, the human body has long been accustomed to these normal changes. In an air-conditio
18、ned living or work environment, however, body temperatures remain well under 37, our normal temperature. This leads to a weakened immune system and thus greater exposure to diseases such as colds and flu.（分数：10.00）(1).What do we know about Legionnaires disease from the passage?（分数：2.00）A.It was the
19、most widely concerned office hazard.B.It can affect people both inside and outside the building.C.It happens only in air-conditioned office buildings.D.It does not develop in well-designed buildings.(2).In the old air-conditioned systems, bacteria first develop _.（分数：2.00）A.in the reservoirsB.in the
20、 ventilation systemC.in the humidifiersD.in the air intake(3).The fact that about half of workers developed the ability to fight off the bacteria may_.（分数：2.00）A.relieve peoples worry about the danger caused by the bacteriaB.help people find an effective way to get rid of the bacteriaC.reflect the s
21、erious danger brought by the bacteriaD.cause serious disease such as cancers to people(4).The author most probably wants the readers to treat biocides with an attitude of_.（分数：2.00）A.cautionB.trustC.enthusiasmD.criticism(5).The last paragraph implies that our immune system can be weakened when_.（分数：
22、2.00）A.we live in an artificial climatic environmentB.there are variations in temperature and humidityC.our body temperatures often remain not high enoughD.we are often exposed to diseases such as colds and fluFor centuries, in the countries of south and Southeast Asia the elephant has been an intim
23、ate part of the culture, economy and religion. And nowhere more so than in Thailand. Unlike its African cousin, the Asian elephant is easily domesticated (驯化). The rare so-called white elephants have actually lent the authority of kingship to its rulers and until the 1920s the national flag was a wh
24、ite elephant on a red background. To the early Western visitors the countrys romantic name was “Land of the White Elephant“. Today, however, the story is very different. Out of work and out of land, the Thai elephant struggles for survival in a nation that no longer needs it. The elephant has found
25、itself more or less abandoned by previous owners who have moved on to a different economic world and a westernized society. And while the elephants problems began many years ago, now it rates a very low national priority. How this reversal from national icon (圣像) to neglected animal came about is a
26、tale of worsening environmental and the changing lives of the Thais themselves. According to Richard Lair, Thailands expert on the Asian elephant and author of the report Gone Astray, at the turn of the century there may well have been as many as 100,000 domestic elephants in the country. In the nor
27、th of Thailand alone it was estimated that more than 20,000 elephants were employed in transport, 1,000 of them alone on the road between the cities of Chiang Mai and Chiang Saen. This was at a time when 90 per-cent of Thailand was still foresta habitat (栖息地) that not only supported the animals but
28、also made them necessary to carry goods and people. Nothing ploughs through dense forest better than a massive but sure-footed elephant. By 1950 the elephant population had dropped to a still substantial 13,397, but today there are probably no more than 3,800, with another 1,350 roaming free in the
29、national parks. But now, Thailands forest covers only 20 per cent of the land. This deforestation (采伐森林) is the central point of the elephants difficult situation, for it has effectively put the animals out of work. This century, as the road network grew, so the elephants role as a beast of burden d
30、eclined.（分数：10.00）(1).What can we know about African elephants from the passage?（分数：2.00）A.It is easy to tame them.B.It is hard to tame them.C.They are living a better life than Asian elephants.D.Their fate is quite similar to that of Asian elephants.(2).Thailand was once called “Land of the White E
31、lephant“ because _.（分数：2.00）A.white elephant is rarely seen and thus very specialB.white elephant was a national symbol until the 1920sC.white elephant has helped kings to gain the ruling authorityD.this name was so romantic that it was popular among visitors(3).Why is the Thai elephant “out of work
32、 according to the author?（分数：2.00）A.Because the elephants are no longer useful to their owners.B.Because their owners are westernized and neglect them.C.Because the government pays little attention to the problem.D.Because there are too many elephants and too few jobs.(4).Which of the following st
33、atements is true about the elephant population at various times?（分数：2.00）A.There were 100,000 tamed elephants at the turn of the century.B.20,000 elephants were employed in transport in Thailand at the turn of the century.C.By 1950 the elephant population in Thailand has been quite small.D.Today the
34、 elephant population is estimated at 5,150.(5).The passage is most probably from _.（分数：2.00）A.a travel magazineB.a history bookC.a research reportD.an official announcementThree key facts about rising sea levels need to be pointed out to the worlds politicians and planners: sea-level rise is now ine
35、vitable, it will happen faster than most of us thought, and it will go on for a very long time. Even if greenhouse gas emissions stopped tomorrow, the oceans will continue to swell as they warm. The climate scientists estimate that sea-level rise could well be in the region of 1 to 2 metres by 2100,
36、 with a small risk of an even greater rise. For many islands and low-lying regions, even small rises will spell disasters. Most countries, however, will only lose a tiny percentage of their land, even with a very big rise. The problem is what has been built on that land: New York, Sydney and Tokyo,
37、to mention just a few cities. Unless something can be done, great areas of urban network will vanish beneath the waves. It will take a massive engineering effort to protect these citiesan effort that may be beyond economies that have been brought to their knees by climate change. None of this means
38、we should despair, and stop trying to ban emissions. But alongside these efforts, we need to start acting now to rrunimise the impact of future sea-level rise. That means we must stop building in the danger zone. Countless billions are being spent on constructing homes, offices, factories and roads
39、in vulnerable coastal areas. For instance, the skyscrapers of Shanghai are being built on land that is a mere 4 metres above sea level on average, and which is sinking under the weight of its buildings and as water is drawn from the rocks beneath them. In cities that have been around for hundreds of
40、 years, this sort of development may be understandable. But planning for new coastal developments is to go against reality. If we want to build a lasting heritage for our children, we should do so on the plentiful land that is in no danger from the sea It is one of the easiest ways to slow down clim
41、ate change, and we should be acting on it now.（分数：10.00）(1).What is the major cause of the rising sea levels?（分数：2.00）A.Greenhouse gas emissions.B.Overdevelopment.C.Governments indecision.D.Climatic changes.(2).New York, Sydney, and Tokyo are mentioned to illustrate the idea that_.（分数：2.00）A.world e
42、conomy will collapse when sea levels riseB.modern cities are usually built along the coastlineC.the coastline is crucial for developed countriesD.most countries will suffer when sea levels rise(3).The effort to protect the coastal cities may be beyond economies because _.（分数：2.00）A.economic developm
43、ent has been accelerating climate changeB.too much money has been spent on fighting climate changeC.climate change has got economies under its controlD.people have lost confidence in their economies(4).What is mentioned as the result of building many skyscrapers in Shanghai?（分数：2.00）A.The sea level
44、on average is sinking.B.The land beneath is sinking.C.Water is drawn from the rocks beneath.D.Buildings become dangerous.(5).“to go against reality“ (Line 2, Para.6) can be explained as _.（分数：2.00）A.impracticalB.unappealingC.courageousD.desirable大学英语四级改革适用（阅读）模拟试卷 283 答案解析(总分：60.00，做题时间：90 分钟)一、Read
45、ing Comprehensio(总题数：6，分数：60.00)1.Part III Reading Comprehension（分数：10.00）_解析：2.Section C（分数：10.00）_解析：If the salinity (含盐量) of ocean waters is analyzed, it is found to vary only slightly from place to place. Nevertheless, some of these small changes are important. There are three basic processes th
46、at cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporationconversion of liquid water to water vapor. In this manner, the salinity is increased, since the salts stay behind. If this is carried to the extreme, of course, white crystals of sal
47、t would be left behind. The opposite of evaporation is precipitation (降水), such as rain, by which water is added to the ocean. Here the ocean is being diluted(稀释) so that the salinity is decreased. This may occur in areas of high rainfall or in coastal regions where rivers flow into the ocean. Thus
48、salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation or runoff (形成地表水部分的降雨). Normally, in tropical regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas. A third process by which
