1 . ______ a running log of your time spent volunteering, you would have received a certificate showing the good you’ve done.

A．If you hadn’t kept

B．Had you kept

C．If you kept

D．Not did you keep

2 . With the deadline drawing near, I am getting more and more anxious about the final exam.         I started to review my lessons several days in advance, I wouldn't have burned the midnight oil last night.

A．If

B．Had

C．Should

D．Were

3 . Had the calculations been done by hand, all practical value ______ by the time they were finished.

A．had lost

B．would lose

C．would have lost

D．should have lost