Hoàn thành các câu sau

1. He.....(go) to aerobics class three times a week
2. You ....(breathe) hard. Sit down a rest for a while
3. Dolphins and whales are mammals. They...(breathe) air
4. We'd better not go out now! It .... (rain) heavily!
5. In our area, it..... (rain) a lot in June
6. Our neighbors..... (dance) again. The music is too loud!
7. Our neighbors... (dance) every saturday evening. Their noisy music disturbs everybody
8. Warm air.....(rise). Cool air.....(fall)
9. Look at that balloon. It ....(rise) very fast. Ooops! I guess popped. Now it ... (fall)