the atmosphere surrounding the earth
water from oceans and lakes
energy from the sun
greenhouse gases in the sky
第1题:
According to the passage which of the following is true?
[A] A fixed star refers a star that is always stationary on the sky.
[B] Scientists can tell the motion of the earth from the motions of other five planets.
[C] Ancient people had scanty knowledge about the movement of the stars.
[D] All the stars on the sky can be seen all the year around.
第2题:
A.water-tube
B.fire-tube
C.exhaust gas
D.composite
第3题:
According to the passage, which is true about the ocean?
A. The waters of the ocean came from rain water.
B. The ocean was formed from the, lighter rock materials.
C. The vast single ocean formed about 200 million years ago.
D. The ocean covered the whole surface of the earth at very beginning.
45.答案为A。选项A符合第二段内容。选项B与原文不符;选项C与第三段最后一句及最后一段不符;选项D与原文第二段最后一句不符。
第4题:
第5题:
第6题:
A greenhouse is a building made of glass which is used for keeping plants when the outside temperature is low. In a similar way there are several gases in the atmosphere which trap(捕捉)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 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 forests. 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(二氧化碳)in the atmosphere doubles, there will probably be a rise in the earth's temperature of between 1 and 4 degrees. 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.
1. The"greenhouse effect"means _____.
A. the way in which gases are used for keeping plants warm
B. a natural course which is some degree helpful to us
C. the way"greenhouse gases"trap heat on the earth
D. the whole course in which greenhouse gases prevent heat
2. If there were no greenhouse effect, _____.
A. no plants would grow on our planet
B. earth would be thirty degrees colder
C. man could not live on the earth
D. All of the above answers are correct
3. Which of the following is NOT true? _____
A. Burning too much coal and oil produces lots of greenhouse gases.
B. It has become warmer 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.
4. Suppose the earth's temperature rose by 3 degrees, _____.
A. great harm would be done to mankind
B. the sea level would go by 10 centimetres
C. all the land in the world would be flooded
D. crops would be unable to grow on the earth
5. This passage mainly deals with _____.
A. the concept(概念)and harm of greenhouse effect
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
第7题:
第8题:
27. From the passage we know that fresh water doesn't come from________ .
A.rivers
B.lakes
C.underground
D.the sea
第9题:
第10题: