Question

A green house is a building made of glass which is used for keeping warm when the outside temperature is low. In a similar way there are several gases in the atmosphere (mixture of gases that surround the earth) which trap the heat produced by the sun and prevent it from escaping. These gases are known as “greenhouse gases”. And the way in which they trap heat in the atmosphere is called the “greenhouse effect”. This is not simply air pollution. Most of the main greenhouse gases exist naturally in small amounts in our atmosphere, and without them the earth would be 30 degrees colder and human life would not exist. In other words, the greenhouse effect is a natural course which is to some degree helpful to us.
The problem is that in the last century and a half, we have been putting too many of these gases into the earth’s atmosphere by burning large quantities of coal and oil and by cutting down forest. The rapid increase in greenhouse gases is making the world warmer. The world’s temperature has already gone up by half a degree this century, and the sea level has risen by 10 centimetres. If the amount of carbon dioxide in the atmosphere doubles, there will probably be a rise in the earth’s temperature of between I and 4℃;. This may seem a small increase, but it would be enough to cause major changes in geography and agriculture. Large areas of the world would be flooded, and some areas would become dry and unable to produce crops. It is important, too, to consider that there may be a delay of about 30 years in the greenhouse effect. This means that we are probably experiencing only now the effect of the gases put into the atmosphere before the 1960s. Since then, our use of these gases has greatly increased.
【小题1】 According to the passage, we can know “greenhouse effect” means_______.  

A．the way in which gases are used for keeping plants warm

B．a natural course that is to a certain degree useful to us

C．the way “greenhouse gases” trap heat on the earth

D．the whole course in which greenhouse gases prevent heat

【小题2】 If there were no greenhouse effect,_______.

A．all plants would not grow on our planet

B．soil would reduce the temperature by 30 degrees

C．man would breathe the cleaner air

D．people couldn’t live in the earth

【小题3】 Which of the following is not true?

A．Burning too much coal and oil produces lots of greenhouse gases.

B．It has become warm on the earth now than in the past.

C．Gases put into the atmosphere now will affect the earth years later.

D．The temperature in a greenhouse is as high as that in the atmosphere.

【小题4】 Suppose the earth’s temperature rose by 3 degrees, _______. 

A．great harm will be done to mankind

B．the sea level would go up by 10 centimeters

C．all the land in the world would be flooded

D．crops would be unable to grow on the earth

【小题5】 This passage mainly deals with ________.

A．the concept (概念) and the harm of the greenhouse

B．the relation between greenhouse gases and man

C．the concept and change of greenhouse effect

D．the effect of the rise of the earth’s temperature

Answer 1

【小题1】B
【小题2】B
【小题3】D
【小题4】D
【小题5】A

解析【小题1】B 从第一段最后一句” the greenhouse effect is a natural course which is to some degree helpful to us.” 可知,答案选B。
【小题2】B 根据常理推断，没有温室气体的话，地球温度会下降30°，大部分植物都不会生存下去，A太绝对，排除。C项不正确，温室气体不是空气污染；D项应该是on the earth.没有温室气体的话，地球上就不会有人类，也就无所谓“人们不能居住在地球上”这一说。
【小题3】D 正误题比较简单，可以用排除法做。大量燃烧煤炭和石油会产生大量的二氧化碳等温室气体，A正确；in the last century and a half，人们向大气层输送了太多的温室气体，导致现在气候的变暖，B正确；现在排放的气体会对以后的环境造成影响，C正确；故选D。
【小题4】D 用排除法，文章提到温度升高会对地理和农业造成大的影响，排除A项；B项是概念混淆，文章只提到海平面上升了10厘米，但并不意味着每次都是正好上升10厘米；根据“some areas would become dry and unable to produce crops.”排除C项；故选D项。
【小题5】A 主旨大意题。文章主要介绍温室气体和温室效应的概念，并提到温室效应的对环境造成和将造成的影响。A项概括得最全面。