Many people are worried about what television has done to the generation of American children who have grown up watching it. For one thing, recent studies show that TV weakens the ability to imagine. Some teachers feel that television has taken away the child’s ability to form mental pictures in his own mind, resulting in children who cannot understand a simple story without pictures. Secondly, too much TV too early usually causes children to be removed from real-life experiences. Thus, they grow up to be passive watchers who can only respond to action, but not start doing something actively. The third area for such a worrying situation is the serious dissatisfaction frequently expressed by school teachers that children show a low patience for the pains in learning. Because they have been used to seeing results of all problems in 30 or 60 minutes on TV, they are quickly discouraged by any activity that promises less than immediate satisfaction. But perhaps the most serious result is the TV effect of bloody fights and death on children, who have come to believe that it is an everyday thing. Not only does this increase their admission of terrible acts on others, but some children will follow anti-social acts that they see on television. What do school teachers worry about

A. [A] Children suffer from mental pains.
B. Children spend little time learning unknown things.
Children become uninterested in class activities.
D. Children are weak at facing difficulties.