用括号内所给单词的适当形式补全短文。

    In our daily life, some people think that smoking can help them relax. In fact, smoking is really  (healthy). Do you know that there are over 4,000 chemicals in cigarettes? These chemicals are bad for our bodies. They can cause cancer and other  (disease). The smoke from cigarettes  (harm) not only smokers but also other people. It's  (call) "second-hand smoke" and it can be  (dangerous) and has higher risks. Smokers shouldn't use smoking to help them relax. They must give up smoking as soon as possible.