2. 考研
  3. In the following text, some sentences have been removed. For Questions 41-45, choose the most suitable one from the list (A、B、C、

In the following text, some sentences have been removed. For Questions 41-45, choose the most suitable one from the list (A、B、C、

admin2010-09-06  56
问题 In the following text, some sentences have been removed. For Questions 41-45, choose the most suitable one from the list (A、B、C、D、E、F、G……) to fit into each of the numbered blank. There are several extra choices, which do not fit in any of the gaps. (10 points)

    (41)______. 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 subtraction 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 precipitation, such as rain, by which water is added to the ocean. Here the ocean is being diluted so that the salinity is decreased. This may occur in areas of high rainfall or in coastal regions where rivers flow into the ocean. (42)______.
    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. (43)______.
    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 beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. (44)______.
    In the Weddell Sea, off Antarctic, the densest water in the oceans is formed as a result of this freezing process, which increases the salinity of cold water. (45)______.

A. The water in the oceans only leaves by evaporating (and the freezing of polar ice), but the salt remains dissolved in the ocean—it does not evaporate.
B. Thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation or runoff.
C. If the salinity of ocean waters is analyzed, it is found to vary only slightly from place to place.
D. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
E. This heavy water sinks and is found in the deeper, portions of the oceans of the world.
F. The salinity (salt content) of ocean water varies. One cubic foot of average sea water contains 2.2 pounds of salt.
G. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.

选项
答案B
解析
转载请注明原文地址:https://kaotiyun.com/show/76Z4777K
0

考研英语一

相关试题推荐
随机试题
最新回复(0)