用所给单词的适当形式填空。 1. I won't leave until it ____ (not) rain. 2. He often hears the boy____ (play) the guitar, 3. If you drink some tea before going to bed, you will be possibly____(wake) and can't easily get to sleep again. 4. I felt ____(tire) after a long time of study. 5. It's important ____(keep) healthy.