There’s no snake known that will habitually attack human beings unless _______ with its life.
A. threaten B. threatened
C. threatening D. having threatened
It is difficult for us to know the truth ______ we’ve actually looked into the case.
A. until B. after
C. since D. if
The news came as no surprise to me. I ______ for some time that the factory was going to shut down.
A. had known B. knew
C. have known D. know
I’d like to start my own business –that’s I’d do if I had the money.
A.why B.when C.which D.what
--- Can David take charge of the international department?
--- I’m afraid it’s ________ his ability.
A. under B. within
C. beyond D. over
E-mail, as well as telephones, ______ an important part in daily communication.
A. is playing B. have played
C. are playing D. play
