大学英语四级阅读理解练习 九

　　Questions 6 to 10 are based on the following passage:　　
　　The concept of obtaining fresh water from icebergs that are pulled to populated areas and dry regions of the world was once treated as a joke more appropriate to cartoons than real life. But now it is being considered quite seriously by many nations, especially since scientists have warned that the human race will outgrow its fresh water supply faster than it runs out of food.
　　Glaciers（冰川，冰河）are a possible source of fresh water that have been overlooked until recently. Three-quarters of the Earth's fresh water supply is still tied up in glacial ice, a reservoir of undeveloped fresh water so immense that it could sustain all the rivers of the world for 1,000 years. Floating on the oceans every year are 7,659 trillion（兆）metric tons of ice wrapped in 10,000 icebergs that break away from the polar ice caps, more than ninety percent of them from Antarctica.
　　Huge glaciers that stretch over the shallow continental shelf give birth to icebergs throughout the year. Icebergs are not like sea ice, which is formed when the sea itself freezes; rather, they are formed entirely on land, breaking off when glaciers spread over the sea. As they drift away from the polar region, icebergs sometimes move mysteriously in a direction opposite to the wind, pulled by pieces of ice , icebergs have been known to drift as far north as 35 degrees south of the equator in the Atlantic Ocean. To surround them and steer them to parts of the world where they are needed would not be too difficult.
　　The difficulty arises in other technical matters, such as the prevention of rapid melting in warmer climates and the funneling（汇集）of fresh water to shore in great volume. But even if the icebergs lost half of their volume in pulling, the water they could provide would be far cheaper than that produced by removing salt from water.
　　6. According to the author, most of the world's fresh water is to be found in ________ .
　　 A) oceans
　　 B) rivers
　　 C) glaciers
　　 D) reservoirs
　　7. The word "it" in Line 3 refers to ___________ .
　　 A) an iceberg that is pulled
　　 B) obtaining fresh water from icebergs
　　 C) the population of dry areas
　　 D) real life
　　8. How are icebergs formed?
　　 A) They break off from glaciers.
　　 B) Seawater freezes.
　　 C) Rivers freeze.
　　 D) Small pieces of floating ice funneling.
　　9．With which of the following ideas would the author be likely to agree?
　　 A) Pulling icebergs to dry areas is economically possible.
　　 B) Removing salt from water. is the best way to obtain drinking water.
　　 C) Using water from icebergs is a very short- term solution to water shortage.
　　 D) Icebergs could not be pulled very far before they would melt.
　　10．It can be inferred from the passage that most icebergs _________ .
　　 A) become part of glaciers
　　 B) drift toward the polar region
　　 C) move in whichever direction the wind is blowing
　　 D) melt in the oceans