阅读理解
D
Young people can have problems with their minds. Some students become worried because they have to study very hard; others have trouble getting on well with people like their parents or classmates.
Li Wei, a junior 2 student from Hefei, could not understand his teacher and did badly in his lessons. He became so worried about it that he started to hurt himself with a knife.
Another 14-year-old student, Yang Fang from Guangzhou, was afraid of exams. She got very nervous, and when she looked at the paper, she couldn't think of anything to write.
In fact, many students have mental (心理的) problems. However, most of them don't ask for advice or help. Some think they will look stupid if they go to a doctor; others don't want to talk about their secrets.
Liang Yuezhu, a teacher, has the following advice for young people:
Talk to your parents or teachers often.
Take part in group activities and play sports.
Go to a doctor if you feel unhappy or unwell.
； DEET在一定条件下，可通过下面的路线来合成： 