英语四级备考中，阅读理解是考生复习的重点和难题，阅读理解部分的得分影响着考生四级成绩的好坏，我们为同学们整理了2023年下半年英语四级仔细阅读模拟训练（16），期望可以为大伙带来帮助。
2023年下半年英语四级仔细阅读模拟训练（16）
If the salinity 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 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 staybehind. 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. Thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation or runoff.
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 whererivers 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 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 Weddell Sea, off Antarctica, the densest water in the oceans is formed as a result of this freezingprocess, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portions of the oceans of the world.
复习资料：
Choose correct answers to the question:
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 Oceans 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. in tropical areas
B. off Antarctica
C. of high rainfall
D. with abundant
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 in 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
以上是新东方在线英语四级频道我们为大伙带来的2023年下半年英语四级仔细阅读模拟训练（16），期望考生们获得出色的成绩，顺利通过四级考试。
