As we all know, smoking is not only harmful to our health, but also harmful to the environment. Smoking can cause many diseases, such as lung cancer. Smoking also affects non-smokers. For passive smokers, their chance of getting ill is even greater than that of smokers. Some young people think that smoking is cool, and some think that smoking can refresh themselves. Nowadays, more and more public places have hung up“non-smoking”signs. This is a big progress we have made. Greater efforts need to be made to ban smoking in public places for the sake of our health.