1. 阅读下面短文，从每题所给的A、B、C、D四个选项中选出能正确回答所提问题或完成所给句子的最佳答案。

    A new study found that people's lives are made shorter in North China. It showed the life expectancy (平均寿命）had been cut down by 5.5 years there. Scientists think that it is because of the heavy air pollution. It is really the truth. Our country has already done something. However, it doesn't seem to work so well.

    "Air pollution is bad for people's health. The harm is much more serious than we can imagine, said Chen Yuyu of Beijing University, one scientist of this study.

    There was serious smog and haze in Beijing in November 2016. The sky was gray and the air smelt strange. Heavy haze covered the city. Highways were closed and planes couldn't take off on time. People couldn't see things clearly even within 15 meters in some places. Some primary schools were closed for several days.

    We should all fight against air pollution and think of good methods to solve the problem. People should be encouraged to take buses, ride bicycles or walk instead of driving cars. The factories that pollute air heavily should be closed.

    "It might be expensive to improve our environment, but we must do it. Protecting our environment means protecting ourselves," Li Hongbin, another scientist, said.

1. （1） Why do people's lives become shorter in North China according to the scientists?

   A . Because the air is heavily polluted. B . Because it's too cold in winter there. C . Because there are too many cars there. D . Because it's too dry there.
3. （2） What does the underlined word "truth" mean?

   A . Fact B . Trick C . Method D . Idea
5. （3） What's the function (功能)of the third paragraph?

   A . To show different ideas of the scientists. B . To use an example to show the serious air pollution. C . To show what we should do to protect the environment. D . To give us some advice about living in Beijing.
7. （4） What can we NOT know from the passage?

   A . Air pollution is more harmful than we can imagine. B . Serious smog and haze can make traffic stop. C . Improving the environment is so expensive that we can't do it. D . People should change their ways of going out.
9. （5） What's the main idea of the passage?

   A . Air pollution in North China is caused by waste gas. B . To save the environment, we should do something more. C . The temperature becomes higher and higher in North China. D . How air pollution in North China has.