Somking is bad in that it is harmful to one's health.In spite of the fact that doctors have even warned that it caused cancer,people still keep on smoking.
In some Western countries,however,people are beginning to kick the bad habit.They realize that health should come first.To help them quit smoking,there are lays against cigarette advertising and smoking in public places.This is praiseworthy(值得赞许的) except that Western countries are now selling cigarettes in the East in greater numbers than ever.That they are doing this is immoral,don't you think?
warn + 人 + against + 名词/动名词 警告某人不要...
The teacher warned the new student against cutting class.
warn+ 人 + of + 事 警告某人某事
this sign warns people of the dangers of swimming too far out.
