用括号内所给单词的适当形式填空。
1. Sally's school orchestra is _____ (play) it.
2. What about _____ (listen) to the concert?       
3. Mr. Wang is our English teacher, so he likes _____ (west) classical music.
4. His sister _____ (go) to America, hasn't she?
5. How many _____ (composer) are there in the hall?