1. If I ____ where he lived， I ____ a note to him.
A. knew， would B. had known， would have sent
C. know， would send D. knew， would have sent
2. If they ____ earlier than expected， they ____ here now.
A. had started， would be B. started， might be
C. had started， would have been D. will start， might have been
3. I didn't know his telephone number. ____ it， I ____ then.
A. Had I known， would ring him up B. Should I know， would have rung him up
C. If I knew; would ring him up D. Had I known; would have rung him up
4. Mary is ill today. If she _____， she ____ absent from school.
A. were not ill， wouldn't be B. had been ill， wouldn't have been
C. ha d been ill， should have been D. hadn't been ill， could be
5. Were I to do it， I ________ it some other way.
