2. keep busy doing不断地，不停地，忙着做某事

1. keep back 　阻止...向前

13. Every few hundred meters along the wall there are watch-towers,　where soldiers　used to keep _____.

12. He walked so fast that I could hardly keep _____　 _____　 him.

11. The good news keeps our　 spirits _____.

10. I see you are getting along well with your English studies.　 Keep _____ the　good work.

9. The rain kept _____ all night.

8. It is also bad manners to keep _____ when the teacher asks you a question.

7. Will this overcoat keep the rain _____?

6. Danger!　 Keep ______!