选择合适的单词，并用其适当形式完成句子。

sleep, asleep, sleepy

1. When did you go to _____ last night?

2. My sister fell _____ when listening to music.

3. I can’t go on working because I feel very _____?

reply, answer

4. I wrote to him many times, but he never _____ to my letters.

5. Who can _____ the teacher’s question