题目：
根据句意，用括号内所给词的适当形式填空。
1. There are some ______(piano) in the room.
2. What club do you want _____ (join)?
3. May I _____ (swim) here?
4. His mother is a ______(music).
5. That is ______ (we) classroom.
答案：
1. pianos 2. to join 3. swim 4. musician 5. our
