假如你是张伟,写一篇英语作文劝john戒烟，告诉他吸烟的危害

Dear John,
I hear that you smoke heavily.Is it right?As you know,many people suffer from lung cancer which derives from smoking most of the time and die at last every year.It's true ,for the datas come from the survey of WHO,which have enough supporting cases.What's more,your family members may feel very sorry ,for they have to live in the place full of second-hand smoking.Perhaps you may pay no attention to them.Only when they fall ill do you realize the severe influence of smoking on them.Do you feel at ease when they are ill?So I hope you would give up smoking and make your family members keep fit.
Sincerely
Zhang Wei