Recently a group of children in America poured some gasoline on a sleeping man and set him on fire. When caught, the children said they had done what they'd seen on TV. The incidents make people angry who believe that American children are harmed by watching too much TV. They claim children can't tell between the fiction of TV and reality, and TV distracts them from learning and makes them violent. To estimate the impact of TV on young people, "Life" magazine hires a company to interview hundreds of school children in Nora Springs, Iowa and in Dallas, Texas. Although the two cities are very different, the company finds children in each city watch the same TV shows. Many Iowa children, who watch an average of three hours of TV a day, recognizing that life on TV is rosier than what they experience. Their favourite shows are situation comedies about American families in trouble. Many boys like violent shows about police detectives or heroes, girls particularly soap operas-stories about families and friends. On the whole, children find real violence on news programs hard to take. "If you see a bus crash on the news, it's frightening," one fifth grader says. By and large, the Iowa children agree that the best thing about TV is it makes you laugh. Children in Dallas are savvier about programs of drug use on TV. "They don't really show them doing it right. On TV they are not real." A fifth grader says. "Life" agrees with a 1988 study by the U. S Department of education that finds children are none the worse for watching TV. The study finds TV doesn't have lasting effect on children. On the contrary, kids show good judgment about what they watch. "There are very few good shows on TV anymore," a 10-year-old boy says. While the debate about TV is so heated, the "Life" survey gives hope that American kids aren't wasting three or four hours a day (what is worse, by the time young people enter college today, they will have devoted more time to watching television than they will spend in college). However, a child watching TV isn't reading a good book or joining in healthful sports. The main idea of the passage is  _  .
children who watch more TV are smarter than those who watch only one hour a day children learn about drugs from watching TV watching too much TV can cause children to go out and kill people children learn from TV and can tell reality from what they see on it