1. 根据句意，用方框中所给单词的适当形式填空。

keep, clean, because, lesson, wonderful

1. （1） You can the books for three weeks.

3. （2） The park is so ! I want to visit it tomorrow.

5. （3） We don't have on Sundays.

7. （4） It's 4:45 p.m. Kangkang and Michael are doing some in the classroom.

9. （5） Meimei is not happy her pet dog is lost.