What do you think of when you hear the word "desert"? We usually think of deserts as hot, dry places. In fact, there are both hot and cold deserts in the world. Scientists defined deserts as areas of land where there are less than ten inches of rainfalls per year and there are few plants. In arctic and Antarctic regions, for example, there is very little rain. Precipitation is almost always frozen in the form of ice or snow. So these regions are considered deserts and given the special label "cold deserts." The low temperature there ranges from 10 to 50°F. in summer and from -50 to 10°F. in winter. Hot deserts, on the other hand, have high temperatures, usually over 75°F. in the daytime. As with cold deserts, there is usually little water available for plant growth. But contrary to what many people think, hot deserts are not lifeless wastelands. These species have learned to adapt to the lack of water and harsh temperatures. Also, they are not necessarily made up of endless shifting sand dunes. _______
AThey are home to a fascinating variety of plants and animals.
BBecause it stays frozen on the ground, plants cannot use it to grow.
CHot deserts, on the other hand, have high temperatures, usually over 75°F. in the daytime.
DIn many hot deserts, the wind has blown away the sand, leaving bare rock, boulders, and gravel.正確答案
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