問題詳情

Scientists believe that something very serious is happening to the Earth. It is becoming warmer. Scientists predictthat there will be major changes in the climate during the next century. Coastal waters will have higher temperatures.17 Farmers will have trouble producing good crops. In warm regions the weather will be too dry. The amount ofwater could decrease by 50 percent. This would cause a large decrease in agricultural production.World temperatures could increase from 1.5 to 5.6 degrees Celsius by the middle of the twenty-first century.18 A rise in temperatures could cause the great ice sheets to melt, which, in turn, would raise the level of theocean by one to two meters. Many coastal cities would be underwater. Why is this happening? Why is the Earthbecoming warmer?The Earth and its atmosphere are kept warm by the Sun. The atmosphere lets most of the light from the Sun passthrough to warm the Earth. The Earth is warmed by the sunlight and sends heat energy back into the atmosphere.Much of this energy escapes from the Earth’s atmosphere. However, some of it remains. 19 Then this heat issent back down to the Earth, and the Earth becomes warmer.Recently, however, an increase of carbon dioxide in the atmosphere is causing serious problems. Too muchcarbon dioxide in the atmosphere prevents heat energy from escaping: too much heat is sent back down to the Earth.20 When oil, gas, and coal burn, they create large amounts of carbon dioxide. The destruction of rain forests thatabsorb carbon dioxide also helps to increase the amount of carbon dioxide in our atmosphere. Some scientists believethat the amount of carbon dioxide in the air will double by the late 2000s.
17
(A) This will have a serious effect on agriculture.
(B) And the amount of carbon dioxide in the atmosphere continues to increase.
(C) Scientists call this warming of the Earth and its atmosphere the “greenhouse effect.”
(D) And the increase in temperature could be even greater in the Arctic and Antarctic regions.

參考答案

答案：A
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)

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