题目内容：

In our daily life, some people think that smoking_____help them relax. In fact, smoking is really______. Do you know that there are over 4,000 chemicals（化学药品） in cigarettes? These chemicals are ______for our bodies. They can cause cancer and _____diseases.

The smoke from cigarettes harms not only smokers but also other people. It’s_____“second-hand smoke” and it can be______and has higher risks. Smokers shouldn’t use smoking____them relax. They must give up smoking as soon as possible.

1.A. must    B. can    C. should

2.A. healthy    B. health    C. unhealthy

3.A. good    B. bad    C. well

4.A. other    B. others    C. another

5.A. called    B. calls    C. calling

6.A. more dangerous    B. dangerous    C. the most dangerous

7.A. help    B. to help    C. helping