If the salinity(含盐量) of ocean waters is analyzed, it is round to vary only slightly fro - 试题答案网问答

第1题

If the salinity（含盐量) of ocean waters is analyzed, it is found to vary only slightly fro

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 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(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 evaporation, or decreased by the addition of fresh water by precipitation or runoff(形成地表水部分的降水).

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.

Choose correct answers to the question: 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

Which of the following processes will increase salinity of ocean waters？A.Evaporation.

B.Precipitation.

C.Melting.

D.Dilution.

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

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

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

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第2题

Climate, more than any other single factor: determines the distributions of life on Earth.

Climatic boundaries establish the limits within which organisms can survive.

Plants, even more than animals, must be well adapted to climate in order to survive. They cannot move about or take shelter but must be equipped to endure whatever weather conditions are likely to occur.

In the harsh conditions of tundra, for example, low growing mosses, lichens, and a few flowering plants all hug the ground for shelter from icy winds.

Animals, despite their ability to move about and find shelters, are just as much influenced by climate as plants are. Creatures such as the camel and the penguin are so highly specialized that they have as extremely limited distribution. Others, such as bears, are flexible enough to adapt to a broad range of climates. Oceandwelling organisms are just as sensitive to climatic changes—in this case temperature and salinity (含盐量)—as land animals. Reef corals can survive only in clear warm seawater. Certain foraminifers are so sensitive to changes in their environment that their presence can be taken as an index of sea temperature. Human beings are among the least specialized of all animals and can live almost anywhere. Their clothes and their homes act as a sort of "miniature climate" that can be taken with them everywhere.

Which of the following is neither plant nor animal？

A．Tundra

B．Reef coral

C．Penguin

D．Camel

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第3题

在正常运行状态下，炉水含盐量应()临界炉水含盐量。

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第4题

水的软硬度测定中，规定硬水含盐量0.03%，软水含盐量0.0005%。（)

水的软硬度测定中，规定硬水含盐量0.03%，软水含盐量0.0005%。 ( )