Nowhere in the world has the issue of tobacco been so much debated as in our society. Nowadays, tobacco is more harmful than drug to people’s health, therefore many people think that smoking is legal that is a direct andprimary reason to induce this kind of problem. The above point is certainly true; this essay will outline three reasons.

　　The main reason is that tobacco is a silent killer to smokers. Tobacco is known to be the probable cause of some 25 different diseases, and for some,such as lung cancer, bronchitis and emphysema, it is the main cause. According to a WHO report four million people die yearly from tobacco-related diseases, that is one death every eight seconds. Tobacco is significantly becoming a greater cause of death and disability than any other single cause.