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.
