根据句意,在答题卷标有题号的横线上,写出括号内所给单词的适当形式。

1.  Little Kitty likes hiding ________ (she) behind the door to frighten her friends.

2.  This term he did ________ (bad) in English than last term. He didn't try his best.

3.  The boy made no mistakes(错误) in his homework because he did it ________ (careful).

4.  These are those ________ (swim) bags. Please take care of them.

5.  My grandfather will have his ________ (ninety) birthday next Sunday.