Smoking is harmful to the smoker's heathy.Smoke may result in a dark teeth and may cause bronchitis and lung deases.When the smokes spead into the air.it will make the air dirty and not good to other people.specially for the kids and old peoples.Smoking in public will disturb others and is not polite as well.Of course.to the ordinary familly，smoking will cost a big money and is a heavy burden for the life。