单选题 Children in the United States are exposed to many influences other than that of their families. Television is the most significant of these influences, because the habit of watching television usually begins before children start attending school. And, by the time that the average child finishes high school, he or she will have spent 18,000 hours in front of a television set as opposed to 12,000 hours in a classroom. Parents are concerned about these figures. They are also concerned about the lack of quality in television programs for children. The degree of violence in many of these shows also worries them. Even if it is unreal — a cartoon cat beating up a cartoon mouse with a baseball bat — this violence may have a negative effect on the young minds exposed to it. Studies indicate that, when children are exposed to violence, they may become aggressive or insecure. Parents are also concerned about the commercials that their children see on television. Many parents would like to see fewer commercials during programs for children. And some parents feel that these shows should not have any commercials at all because young minds are not mature enough to deal with the claims made by advertisers. Educational television has no commercials and has programs for children that many parents approve of. The most famous of these is ''Sesame Street'' , which tries to give preschool children a head start in learning the alphabet and numbers. It also tries to teach children useful things about the world in which they live. Even though most parents and educators give ''Sesame Street'' and shows like it high marks for quality, some critics argue that all television, whether educational or not, is harmful to children. These critics feel that the habit of watching hours of television every day turns children into bored and passive consumers of their world rather than encouraging them to become active explorers of it. We still do not know enough about the effects of watching television to be able to say whether or not it is good for children. Until we do, perhaps it would be wise to put a warning on television sets such as the one on cigarette packages: ''Caution: Watching Too Much Television May Be Harmful to Your Child''s Developing Mind. ''

单选题 We can infer from the text that________.

单选题 Which of the following is NOT mentioned in the text about some parents'' attitudes toward commercials?

单选题 Some critics argue that children should not watch TV because________.

单选题 Which of the following is the author''s opinion?

单选题 The best title for the text would be________.