题目内容：

根据句意，写出括号内所给单词的适当形式。

1.Listening to music or visiting interesting places can make you forget your         (sad).

2.As we all know China         (successful) sent up her first man-made satellite in 1970.

3.It's very         ( polite) that she left without any words.

4.The        (angry) the mother is, the more scared the children become.