大学英语四级改革适用（阅读）模拟试卷283
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3. Reading Comprehension
Part III Reading Comprehension
学费减免Section C
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 the small changes are important. There are three basic process that cau a change in oceanic salinity. One of the is the subtraction of water from the ocean by means of evaporation—conversion of liquid water to water vapor. In this manner, the salinity is incread, since the salts stay behind. If this is carried to the extreme, of cour, white crystals of salt would be left behind. The opposite of evaporatio
n 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 decread. This may occur in areas of high rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be incread by the subtraction of water by evaporation, or decread 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 a, 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 a ice. When awater is frozen, the dissolved materials are left behind. In this manner, awater directly beneath freshly-formed a ice has a higher salinity than it did before the ice appeared. Of cour, when this ice melts, it will tend to decrea the salinity of the surrounding water. In the Weddell Sea, off Antarctica, the denst water in the oceans is. formed as a result of this freezing process, which increas 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 Caus of the Changes in Salinity of Ocean Water
C Different Oceans Have Different Salinity
D The Precipitation and Evaporation of Oceans眼睛英语
2.
Which of the following process will increa salinity of ocean waters?
A Evaporation.
B Precipitation.
C Melting.
D Dilution.
3.
According to this passage, the a _____ is likely to have the lowest salinity.
A in tropical areas
B off Antarctica
C of high rainfall
D with abundant sunshine
4.
一个日一个军
The Weddell Sea_____.
A is a good example of incread salinity in freezing a water
B is much larger in area than the Arctic oceans
C has a much lower salinity now than ever
办公室风水
D has the denr water in its upper parts
5.
Coastal regions are mentioned as cas where _____.
A a water is less salty becau fresh water joins in
B rivers carry industrial exhaust into a
C a ice tends to melt more quickly than in the center of oceans
D heavy water sinks to the deeper portions of the oceans
Although many of us may feel air-conditioners bring relief from hot, humid or polluted outside air, they po many potential health hazards. Much rearch has looked at how the movement of air inside a clod environment—such as an office building—can spread dia or expo people in the building to harmful chemicals. One of the more widely publicized dangers is that of Legionnaire's dia, 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 system's cooling towers was somehow sucked back into the air intake (通风口), in most cas due to poor design. The warm air, filled with bacteria, **bined 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 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, th
e water ud for this process is kept in special rervoirs, the bottoms of which provide 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 to fight off the organisms found at the bottom of system rervoirs. But chemicals called "biocides" are added to rervoirs to make them germ-free, and they are dangerous in their own right in sufficient quantities, as they often **pounds strongly linked to cancers. Finally, it should be pointed 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 the normal changes. In an air-conditioned 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 dias such as colds and flu.
6.
瘦脸针后遗症What do we know about Legionnaire's dia from the passage?
五种能力A It was the 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.
7.
In the old air-conditioned systems, bacteria first develop _____.
A in the rervoirs
B in the ventilation system
木兰从军的故事
C in the humidifiers
D in the air intake
8.
The fact that about half of workers developed the ability to fight off the bacteria may_____.
A relieve people's worry about the danger caud by the bacteria
B help people find an effective way to get rid of the bacteria
C reflect the rious danger brought by the bacteria
D cau rious dia such as cancers 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 variations in temperature and humidity
C our body temperatures often remain not high enough
D we are often expod to dias such as colds and flu
For centuries, in the countries of south and Southeast Asia the elephant has been an intimate 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 white elephant on a red background. To the early Western visitors the country's 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 itlf more or less abandoned by previous owners who have moved on to a different economic world and a westernized society. And while the elephant's 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 worning environmental and the changing lives
of the Thais themlves. According to Richard Lair, Thailand's 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 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 forest—a habitat (栖息地) that not only supported the animals but also made them necessary to carry goods and people. Nothing ploughs through den 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, Thailand's forest covers only 20 per cent of the land. This deforestation (采伐森林) is the central point of the elephant's difficult situation, for it has effectively put the animals out of work. This century, as the road network grew, so the elephant's role as a beast of burden declined.
