Question

    Global warming happens when greenhouse gases trap heat and light from the sun in the earth’s atmosphere, which increases the temperature. This is like when heat is trapped in a car. On a hot day, the car gets hotter when it is out in the parking lot. This is because the heat and light from the sun can get into the car, by going through the windows，but it can’t get back out. This is what the greenhouse effect does to the earth .The heat and light can get through the atmosphere, but it can’t get out .As a result, the temperature rises.

Sometimes the temperature can change in a way that helps us. The greenhouse effect makes the earth appropriate for people to live on. Without it, the earth would be freezing, or it would be burning hot. It would be freezing at night because we would not get the sun’s heat and light. During the day, especially during the summer, it would be burning because the sun would be up with no atmosphere to filter(过滤) it, so people, plants, and animals would be exposed to all the light and heat.

Although the greenhouse effect makes the earth able to have people living on it, if there gets to be too many gases, the each can get unusually warmer, and many plants, animals and people will die. Plants would die because they would not be able to take the heat .This would cause us to have less food to eat, and it would also limit the food that animals have. With less food for the animals that we need to survive we would even have less food. Gradually, people, plants, and animals would all die of hunger.

People are doing many things to try to stop global warming. One thing is carpooling-driving with someone to a place that you are both going to. Another thing is being more careful about leaving electrical devices turned on. Now, more people are even riding buses or bikes to lower the amount of greenhouse gases in the air .Although adults do many things to help stop global warming, kids call do just as much.

1.By the example given in Paragraph l, the author wants to__________.

A.explain how global warming happens

B.show his feeling in a car in hot summer

C.tell us cars are causes of greenhouse gases

D.say that I there are greenhouse gases in every car

2.The underlined word “it” in Paragraph 2 refers to__________.

A.light B.greenhouse effect

C.temperature D.heat

3.What is the effect of atmosphere?

A.IT only traps the heat of the sun.

B.It does great harm to humans.

C.It makes the earth neither to hot nor too cold.

D.It prevents all the light from the sun shining on the earth.

4.What is the main idea of the third paragraph?

A.lf there is greenhouse effect all the plants will die

B.Human beings are likely to disappear from the earth

C.Crops can’t take in the heat lf there is greenhouse effect

D.Although greenhouse effect is necessary. Too much of it will cause us to die.

Answer

1.A

2.B

3.C

4.D

【解析】

这是一篇说明文。文章介绍了温室效应和温室气体的作用和影响，人们也在做许多事情试图阻止全球变暖。

1.

推理判断题。根据第一段中Global warming happens when greenhouse gases trap heat and light from the sun in the earth’s atmosphere, which increases the temperature. 当温室气体将来自太阳的热量和光困在地球大气层中，从而导致温度升高时，全球变暖就发生了。可知，文章第一段作者给出浅显易懂的例子，其目的是给读者解释全球变暖的原因。故选A项。

2.

词义猜测题。根据第二段中代词it的前一句The greenhouse effect makes the earth appropriate for people to live on. 温室效应使地球适合人类居住。如果没有温室气体，地球就会冻僵，或者炙热。由此可知此处的代词it代指greenhouse。故选B项。

3.

推理判断题。根据第二段中The greenhouse effect makes the earth appropriate for people to live on.温室效应使地球适合人类居住Without it, the earth would be freezing, or it would be burning hot. 没有它，地球要么会结冰，要么会变得酷热难当。由此判断出大气使得地球不热也不冷。故选C项。

4.

主旨大意题。根据第三段中Although the greenhouse effect makes the earth able to have people living on it, if there gets to be too many gases, the each can get unusually warmer, and many plants, animals and people will die. 虽然温室效应使地球能够有人居住，但如果有太多的气体，每一种都会变得异常温暖，许多植物、动物和人将会死亡。可知，本段主要讲述了温室效应的气体太多会影响生物，因此第三段的主旨大意是“虽然温室效应是必要的。太多会导致我们死亡。”。故选D项。