题目内容
Have you ever seen a greenhouse? Most greenhouses look like a small glass house.
Greenhouses are used to grow plants, especially in winter.Greenhouses work by trapping heat from the sun, the glass panels(板) of the greenhouse let light in, but keep heat from escaping.This causes the greenhouse to heat up, much like the inside of the parked in sunlight, and keeps the plants warm enough to live in winter.
The earth's atmosphere is all around us.It is the air that we breathe.Greenhouse gases in the atmosphere behave much like the glass panels in a greenhouse.Sunlight enters the Earth's atmosphere, passing through the blanket of greenhouse gases.As it reaches the Earth's surface, land, water, and biosphere(生物圈), they take up the sunlight's energy.Once the heat is taken up, this energy is sent back into the atmosphere.Some of the energy passes back into space, but much of it remains trapped in the atmosphere by the greenhouse gases, causing our world to heat up.
The greenhouse effect is important.Without the greenhouse effect, the Earth would not be warm enough for humans to live.But if the greenhouse effect becomes stronger, it could make the earth warmer than usual.Even a little extra warming may bring problems to humans, plants, and animals.
根据材料内容选择最佳答案，并将其标号填入题前括号内。
1.What are greenhouses used for?
A. Growing plants, especially in summer.
B. Growing plants, especially in winter.
C. Heating the house for people to live.
D. Cooking in winter.
2.Why is the temperature in the greenhouse higher than that outside?
A. Because greenhouse can heat itself.
B. The plants inside can produce heat.
C. The glass penal can produce heat.
D. The greenhouse can trap heat from the sun.
3.The underlined word atmosphere probably means________.
A. 大气层 B. 环境 C. 生态链 D. 表面
4.If we didn't have the greenhouse effect，what would happen?
A. We wouldn’t have enough air to breathe.
B. We would have problems, such as global warming.
C. The earth would become too hot to live.
D. The earth wouldn’t be warm enough for us to live.
5.From the article mainly we can learn_____________.
A. The green house has glass penals which can trap heat from the sun.
B. Greenhouses are used to grow plants.
C. Greenhouses are actually greenhouse gasses.
D. What the greenhouse effect is and its influence.
