When talk with children about their school life, the naguhtest boy in their class is mentioned most. The boys has something in common, such as speaking aloud during class and having a bad academic achievement. If there are over two such boys in one class, other students can be effected nagatively. Teachers are usually afraid of facing this kind of students, but the things always get out of their wish. In fact, these boys can't control their own behaviours well due to their slow brain develeopment. They can't sit still like others, but they also hope to get teachers' attention by doing something unusual. As for teachers, a class is a place for children to listen to them and gain new knowledges. Only when they allow their students to talk about something, they could be go-as-you-please. So, a disruptive can be a trouble for teachers and other students in a class, but they need to be respected by others at school. According to my experience, sometimes they are good at sports. Teachers can give their a chance to show themselves on the sports events. Maybe this can be the best way to solve this eternal problem.