题目内容
（请给出正确答案）
Directions: There are 20 blanks in the following passage, and for each blank there are 4 c
Scientists say that something very serious is happening to the earth. It will begin to get __56__ in the following years. There will be major changes in ___57__ in the new century. Coastal waters will have a __58__ temperature. This will have a __59__ effect on agriculture. In northern areas, the __60__ season will be ten days longer by the year 2010. However, in warmer areas, it will be too dry. The __61__ of water could __62__ by eighty percent. This would __63__ a large decrease in agriculture production.
World temperature could __64__ two degrees centigrade by the year 2040. However, the increase could be three times as great in the Artic and Antarctic area. This could cause the __65__ sheets to melt and raise the __66__ of the oceans __67__ one to two meters. Many coastal cities would be __68__ water.
Why is this happening？ There is too __69__ carbon dioxide in the air. __70__ oil, gas and coal burn, they create large amounts of carbon dioxide. This carbon dioxide lets __71__ enter the earth’s atmosphere and __72__ the earth. However, it doesn’t let as much heat __73__ the atmosphere and enter space. It’s like a blanket. The heat __74__ the sun can pass through the blanket to warm the earth. The heat __75__ there and can’t escape through the blanket again.
Scientists call this the green-house effect.
56. A warmer B colder C better D worse
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