When you imagine the desert, you probably think of a very hot place covered with sand. Although this is a good description for many deserts, Earth’s largest desert is actually a very cold place covered with ice: Antarctica.
In order for an area to be considered a desert, it must receive very little rainfall. More specifically, it must receive an average of less than ten inches of precipitation—which can be rain, sleet, hail, or snow—on the ground every year. Antarctica, the coldest place on earth, has an average temperature that usually falls below the freezing point. And because cold air holds less moisture than warm air, the air in Antarctica does not hold much moisture at all. This is evident in the low precipitation statistics recorded for Antarctica. For example, the central part of Antarctica receives an average of less than 2 inches of snow every year. The coastline of Antarctica receives a little bit more—between seven and eight inches a year. Because Antarctica gets so little precipitation every year, it is considered a desert.
When precipitation falls in hot deserts, it quickly evaporates back into the atmosphere. The air over Antarctica is too cold to hold water vapor, so there is very little evaporation. Due to this low rate of evaporation, most of the snow that falls to the ground remains there permanently, eventually building up into thick ice sheets. Any snow that does not freeze into ice sheets becomes caught up in the strong winds that constantly blow over Antarctica. These snow-filled winds can make it look as if it is snowing.
Even though snowfall is very rare there, blizzards are actually very common on Antarctica.
Questions
1) The main purpose of paragraph 1 is to
A. accept a conclusion
B. introduce an argument
C. provide a brief history
D. deny a common belief
2) The best title for this passage would be
A. Earth’s Many Deserts
B. Antarctica: The Coldest Place on Earth
C. A Desert of Ice
D. Unusual Blizzards
3) Africa’s Sahara Desert is the second-largest desert on earth. Based on the information in the passage, what characteristic must the Sahara share with Antarctica?
A. low temperatures
B. high temperatures
C. frequent blizzards
D. low precipitation
4) As used in paragraph 2, which is the best definition for precipitation?
A. moisture in the air that falls to the ground
B. any type of weather event
C. weather events that only happen in very cold areas
D. a blizzard that occurs in areas with limited snowfall
5) In paragraph 2 the author writes, "And because cold air holds less moisture than warm air, the air in Antarctica does not hold much moisture at all." Using this information, it can be understood that
A. air in Africa holds more moisture than the air in Antarctica
B. air surrounding a tropical island holds less moisture than the air in Antarctica
C. air in the second floor of a house is typically warmer than air on the first floor
D. air at the mountains is typically colder than the air at the beach
6) According to the final paragraph, any snow that falls over Antarctica
I. becomes part of the Antarctic ice sheet
II. is blown around by strong winds
III. evaporates back into the atmosphere
A. l only
B. I and II only
C. II and III only
D. I, II, and III
7) Based on the information in the final paragraph, it can be understood that blizzards in Antarctica are mainly the result of
A. freezing cold temperatures
B. large amounts of snowfall
C. low amounts of precipitation
D. strong winds