They are always singing songs to ________ their spirits when they meet with trouble.[ ]

按字母表顺序排列的一组字母是 。

Nowadays, children are ________ too many violent online games, which is bad for the development of their characters.

I used to follow ______ my parents said.—I disagree! I suggested that you ______ yourself.

_____ in the library regulations that any book borrowed be returned by due time, or the borrower will be fined．