25. Where have you been ____ you left home?　　　　　 A. before　　 B. as　　 C. since　　 D. when

24.____ you told me, I had heard nothing of what happened.　 A. Till　 B. Until　 C. After　 D. Since

23. He ran off____ I could stop him.　　　　　 A. before　 　　B. after　　　 C. since　　　 D. when

22. We should pay attention ____ to industry ____ to agriculture.

A. either, or　　 　 B. neither, nor　　 C. not, but　　　 D. both, and

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