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

15. We arrived at the station ____ the train had left.   

A. after   B. before   C. since   D. when