1. 阅读理解

A few years ago, people smoked everywhere. Smoking causes all kinds of illnesses and they might make people sick. However, doctors learned that it was bad for non-smokers, too. Smokers breathe out second-hand smoke, and non-smokers have to breathe it in.

However, there is another problem. When secondhand smoke goes away, it leaves third-hand smoke behind. Third-hand smoke is also bad for our health and it's even harder to get rid of it!

When someone smokes in a place, the smoke leaves chemicals on the walls, floors and even furniture. These chemicals are third-hand smoke. Over time, there will be more and more of it. It can hurt you even if you don't breathe it in. Just touching it will hurt you as well. These chemicals are really bad for our health.

Third-hand smoke is bad for kids. It stays on their clothes and toys. If kids put those things into their mouths, third-hand smoke will get into their bodies. It makes children get sick more often. It can cause death in babies.

If you can smell smoke, third-hand smoke is around. You can wash it away, but you had better stop doing so. There is only one way to stop smoke — all places must be no-smoking even homes and cars.

1. （1） What does the underlined word "it" refer to?

   A . The problem. B . Second-hand smoke. C . Third-hand smoke. D . The chemical.
3. （2） Why is third-hand smoke bad for our health?

   A . Because there is too much third-hand smoke around us. B . Because people don't get used to it. C . Because we can breathe it in easily. D . Because the chemicals in it are harmful to us.
5. （3） How can we avoid (避免) third-hand smoke completely?

   A . By moving into new houses. B . By washing it away. C . By staying away from it. D . By stopping smoking everywhere.
7. （4） What can we know from the passage?

   A . Smoking is only bad for smokers. B . The air will be clean if second-hand smoke goes away. C . It is less difficult for people to clean off third-hand smoke. D . Third-hand smoke can make babies die.