���˸߿�

　　Passage 5

　　The Antarctic （南极洲） is actually a desert. It is the only continent on the earth without a river or a lake.

　　The Antarctic is all ice all year round. The warmest temperature ever recorded there is zero， at the South Pole. Explorers used to think that a place so cold would have a heavy snowfall. But less than ten inches of snow falls each year. That is less than half an inch of water. Ten times that much moisture falls in parts of the Sahara.

　　The little snow that falls in Antarctic never melts. It continues to pile up deeper and deeper year after year. When the snow gets to be about eighty feet deep it is turned to ice by the weight of the snow above it.

　　1. Antarctica is called a desert because it ______.

　　A. is sandy

　　B. has the same temperature as a desert

　　C. has little moisture and no lakes or rivers D. All of the above 1. C

　　2. The Antarctic has ______.

　　A. ten times as much moisture as the Sahara

　　B. the same amount of moisture as the Sahara

　　C. about one-tenth the moisture of the Sahara

　　D. None of these. 2. D

　　3. The temperature in the Antarctic is ______.

　　A. always above zero B. always below zero C. never recorded D. Both B and C 3. B

　　4. The snow in Antarctic is very deep because it ______.

　　A. never stops falling

　　B. piles up year after year

　　C. never melts

　　D. Both B and Cpile up 增多，积累

　　4. D

　　5. The snow turns to ice when ______.

　　A. it gets wet B. the temperature gets colder C. the next snowfall comes

　　D. the snow above it is heavy enough 5. D