Smoking is harrnful to health.Medical science has now proved that smoking cancause lung cancer and other diseases such as emphysema.Your chances of having a heartattack also increase the more you smoke.Smoking is dafinitely a health hazard.

　　吸烟对健康有害。医学已经证明吸烟能引起肺癌和其它疾病, 如肺气肿。吸烟越多, 得心脏病的机会也会增加。无疑吸烟对健康有害。