Saving the earth（Reference for Teaching）
nowadays，watching tv has become part of people's life in most families.although there are many excellent programmes for children, many people feel it harmful for
them.there are several reasons for this.
first of a11，some programmes are not good for children to watch.secondly，television can affect children's eyesight.thirdly，if they watch tv too long each day，they won't be able to finish their homework in time.also，if they stay up too late at night watching tv.they will feel sleepy in class，and thus won't be able to follow others.
so watching too much television can be harmful to children，both mentally and physically.parents should know what programmes their children are watching.every coin has two sides.children must be under control when they watch television.