1、大学英语四级改革适用（阅读）模拟试卷 283及答案与解析 Section C 0 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 that cause a change in oceanic salinity. One of these is the su
2、btraction of water from the ocean by means of evaporation conversion 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 salt would be left behind. The opposite of evaporation is preci
3、pitation (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 salinity may be increased by the subtraction of water by e
4、vaporation, 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 reg
5、ions 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. When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly bene
6、ath 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 Weddell Sea, off Antarctica, the densest water in the oceans is. formed as a result of this freezing process, w
7、hich increases the salinity of cold water. This heavy water sinks and is found in the deeper portions of the oceans of the world. 1 The best title of the passage can be “_“. （ A） Typical Oceans and Their Respective Features （ B） The Causes of the Changes in Salinity of Ocean Water （ C） Different Oce
8、ans Have Different Salinity （ D） The Precipitation and Evaporation of Oceans 2 Which of the following processes will increase salinity of ocean waters? （ A） Evaporation. （ B） Precipitation. （ C） Melting. （ D） Dilution. 3 According to this passage, the sea _ is likely to have the lowest salinity. （ A
9、） in tropical areas （ B） off Antarctica （ C） of high rainfall （ D） with abundant sunshine 4 The Weddell Sea_. （ A） is a good example of increased salinity in freezing sea water （ B） is much larger in area than the Arctic oceans （ C） has a much lower salinity now than ever （ D） has the denser water i
10、n its upper parts 5 Coastal regions are mentioned as cases where _. （ A） sea water is less salty because fresh water joins in （ B） rivers carry industrial exhaust into sea （ C） sea ice tends to melt more quickly than in the center of oceans （ D） heavy water sinks to the deeper portions of the oceans
11、 5 Although 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 environment such as an office buildingcan spread disease or expose people in the buildin
12、g 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 systems in which warm air pumped out of the systems cooling towers was somehow sucked
13、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 showed that even people outside such buildings were at risk if they walked past air e
14、xhaust 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 provide breeding grounds for bacteria which can find their way into the ventilation
15、 (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 to fight off the organisms found at the bottom of system reservoirs. But chemic
16、als 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 pointed out that the artificial climatic environment created by air-conditioners
17、 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-conditioned living or work environment, however, body temperatures remain well under 37
18、 , our normal temperature. This leads to a weakened immune system and thus greater exposure to diseases such as colds and flu. 6 What do we know about Legionnaires disease from the passage? （ A） It was the most widely concerned office hazard. （ B） It can affect people both inside and outside the bui
19、lding. （ C） It happens only in air-conditioned office buildings. （ D） It does not develop in well-designed buildings. 7 In the old air-conditioned systems, bacteria first develop _. （ A） in the reservoirs （ B） in the ventilation system （ C） in the humidifiers （ D） in the air intake 8 The fact that a
20、bout half of workers developed the ability to fight off the bacteria may_. （ A） relieve peoples worry about the danger caused by the bacteria （ B） help people find an effective way to get rid of the bacteria （ C） reflect the serious danger brought by the bacteria （ D） cause serious disease such as c
21、ancers to people 9 The author most probably wants the readers to treat biocides with an attitude of_. （ A） caution （ B） trust （ C） enthusiasm （ D） criticism 10 The last paragraph implies that our immune system can be weakened when_. （ A） we live in an artificial climatic environment （ B） there are v
22、ariations in temperature and humidity （ C） our body temperatures often remain not high enough （ D） we are often exposed to diseases such as colds and flu 10 For centuries, in the countries of south and Southeast Asia the elephant has been an intimate part of the culture, economy and religion. And no
23、where 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 white elephant on a red background. To the early Weste
24、rn 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 itself more or less abandoned by previous owners who
25、 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 tale of worsening environmental and the changing li
26、ves 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 north of Thailand alone it was estimated that more tha
27、n 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 forest a habitat (栖息地 ) that not only supported the animals but also made them necessary to carry goods and peopl
28、e. 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 national parks. But now, Thailands forest covers
29、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 declined. 11 What can we know about African eleph
30、ants from the passage? （ 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. 12 Thailand was once called “Land of the White Elephant“ because _. （ A） white elephant is rarely s
31、een and thus very special （ B） white elephant was a national symbol until the 1920s （ C） white elephant has helped kings to gain the ruling authority （ D） this name was so romantic that it was popular among visitors 13 Why is the Thai elephant “out of work“, according to the author? （ A） Because the
32、 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. 14 Which of the following statements is true about the elephant p
33、opulation at various times? （ 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 elephant population is estima
34、ted at 5,150. 15 The passage is most probably from _. （ A） a travel magazine （ B） a history book （ C） a research report （ D） an official announcement 15 Three key facts about rising sea levels need to be pointed out to the worlds politicians and planners: sea-level rise is now inevitable, it will ha
35、ppen 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, with a small risk
36、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, to mention just a f
37、ew 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 cities an effort that may be beyond economies that have been brought to their knees by climate change. None of this means we should despair,
38、 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 in vulnerable coas
39、tal 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 years, this sort
40、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 climate change, and we
41、 should be acting on it now. 16 What is the major cause of the rising sea levels? （ A） Greenhouse gas emissions. （ B） Overdevelopment. （ C） Governments indecision. （ D） Climatic changes. 17 New York, Sydney, and Tokyo are mentioned to illustrate the idea that_. （ A） world economy will collapse when
42、sea levels rise （ B） modern cities are usually built along the coastline （ C） the coastline is crucial for developed countries （ D） most countries will suffer when sea levels rise 18 The effort to protect the coastal cities may be beyond economies because _. （ A） economic development has been accele
43、rating climate change （ B） too much money has been spent on fighting climate change （ C） climate change has got economies under its control （ D） people have lost confidence in their economies 19 What is mentioned as the result of building many skyscrapers in Shanghai? （ A） The sea level on average i
44、s sinking. （ B） The land beneath is sinking. （ C） Water is drawn from the rocks beneath. （ D） Buildings become dangerous. 20 “to go against reality“ (Line 2, Para.6) can be explained as _. （ A） impractical （ B） unappealing （ C） courageous （ D） desirable 大学英语四级改革适用（阅读）模拟试卷 283答案与解析 Section C 【知识模块】 仔
45、细阅读 1 【正确答案】 B 【试题解析】 主旨大意题。 本文第 1段第 3句是全文的主题句，告诉读者有三种原因致使海洋盐分变化，并逐一介绍这三种原因，选项 B比较全面地归纳了本文的主题。选项 A和 C中心词为 oceans，不妥，选项 D只提及了前面两种原因，不全面。 【知识模块】 仔细阅读 2 【正确答案】 A 【试题解析】 事实细节题。只要明白第 1段第 5句中的 in this manner是指第 4句中的 evaporation，不难做出正确选择。选项 B、 C会使含盐量减少，很容易排除。具体的反证分别出现在第 2段首句、第 3段尾句和第 4段首句。 【知识模块】 仔细阅读 3 【正
46、确答案】 C 【试题解析】 推理判断题。综合 3种情况，造成海洋含盐量低的原因有：降雨多、日晒少、远离热带和海冰融化，由此可推断选项 C最符合。 A和 D是使海水含盐量增加的，因此可排除。 B是否一定海水含盐低，文中并未提到。 【知识模块】 仔细阅读 4 【正确答案】 A 【试题解析】 推理判断题。选项 A是对最后一段第 1句的同义改写。同一句可知选项 C错。选项 B根本没有提及。文章最后一句表明 D正好与事实相反。 【知识模块】 仔细阅读 5 【正确答案】 A 【试 题解析】 推理判断题。 coastal regions字眼在文章中提到两遍，分别在第 2段第 3句及第 3段最后一句。只要能够
47、迅速查找到任何一处均可做出正确判断为A。 B和 C无原文支持； D张冠李戴，原文提及 D内容涉及的是 Weddell Sea，而非 coastal regions。 【知识模块】 仔细阅读 【知识模块】 仔细阅读 6 【正确答案】 B 【试题解析】 事实细节题。本题主要考查复合句的理解。第 2段最后一句表明 B是正确选项。选项 A中的 most和 C中的 only都太绝对了，文中并未对选项 A和C中的相关说法加以这样的限定。选项 D也太绝对了，第 2段第 3句只是说到 “大多数情况下是因为空调设计欠佳所致 ”，并不是说所有设计良好的大厦就不会发生这种情况。 【知识模块】 仔细阅读 7 【正确答
48、案】 A 【试题解析】 事实细节题。本题考查复合句的理解。只要明白第 3段第 2句这个非限制性定语从句中的 the bottoms of which中的 which是指上文的 reservoirs，问题就不难解决了。 【知识模块】 仔细阅读 8 【正确答案】 C 【试题解析】 事实细节题。本题考查 被动语态长句的理解。在第 3段第 3句中，关键词是 highlight，选项 C是对原句主谓部分的近义替换。选项 A和 B在文中皆无提及，选项 D是过度使用生物杀灭剂的后果，与本题干的情况无关。 【知识模块】 仔细阅读 9 【正确答案】 A 【试题解析】 观点态度题。第 3段最后两句讨论生物杀灭剂的
49、用处，其中最后一句中的 but， dangerous和 cancers等词说明作者认为要慎用这种杀灭剂。作者并没对杀灭剂全盘否定，只是说过量使用会引发危险，因此选项 D不对。 【知识模块】 仔细阅读 10 【正 确答案】 C 【试题解析】 推理判断题。本题考查代词的理解。解题的关键在于理解最后一句中的 This是指上一句所说的情况。选项 A中所说的人造环境不是使免疫系统变弱的必然条件。选项 B是保持免疫系统健康的条件。选项 D是免疫系统变弱后的影响。 【知识模块】 仔细阅读 【知识模块】 仔细阅读 11 【正确答案】 B 【试题解析】 事实细节题。本题考查对比处。根据文章第 1段第 3句：和非洲象不同，亚洲象容易驯养，言下之意就是：非洲象不易驯养。答案中用 tame替代原文的 domesticate，意 思相同。选项 A与原文意思正好相反；选项 C， D原文根本未提到。 【知识模块】 仔细阅读 12 【正确答案】 B 【试题解析】 推理判断题。根据文章第 1段第 4句可知当时白象是泰国的国家象征，因此 B为正确选项。本题最具干扰性的是选项 D，在形式上，选项 D与第 1段最后一句极为相似，但是，游客这样称呼泰国，原因也是因为白
