青少年犯罪是一个严重的社会问题。

___Juvenile crime is a serious social issue.

在犯罪的许多方面中，研究人员一直在深入研究青少年犯罪。

Among many aspects of crime, researchers have been keenly studying ___juvenile crime.

图书馆有一个专门的青少年文学区。

The library has a special section for ___juvenile literature.