21. My sister is expecting me,____ I must be off now.　　　 　 A. however　 B. or　 C. so　　 D. otherwise

20. Do not make the same mistake ____ I did.　　　　　　 A. so　　　 B. as　　 　C. like　　　 D. that

19. Hurry up, ____ you'll be late.　　　　 A. or　　　　 B. and　　　　　　 C. so　　　　　 D. yet

18. The worker hunted for jobs in New York for months,____ he could not find any work.

A. and　　　　　 B. yet　　　　　 　 C. or　　　　　 　 D. and but

17. Give me one more minute ____ I'll have finished.　　　　 A. so　 B. until　 C. and　　 D. when

16.____ he was in poor health, he worked just as hard as everyone else.

A. But　　　　　 B. Although　　　 　　　 C. Even if　　　 D. If

15. We arrived at the station ____ the train had left.　 A. after　 B. before　 C. since　 D. when

14.___he daydreamed, Peter saw figures in the sky.　　　　　 A. Until　 B. Since　 C. While　 D. During

13.____ to New York, her father has not heard from her.

A. Because she went 　　 　　　 B. After she went　　　　　 C. When she went　 　　　 D. Since she went

12. It looks ____ it's going to rain.　　　　　　　　　　 A. that　 　　B. as　 　C. as if　 　　D. like that