Only in 1996 the determination and patience of the scientists with a breakthrough at last .
| A．were ; paid off | B．did; pay back | C．did ; pay off | D．did ; pay for |
He regards that book _____ one of the worst that he’s _____ read.
| A．to be, ever | B．to be, never | C．as, ever | D．as, never |
We’re so busy that no one in the office can _____ for any other work.
| A．spare | B．be spared | C．share | D．be shared |
It’s a very kind offer, but I really _____ accept it.
| A．mustn’t | B．needn’t | C．can’t | D．don’t |
That car nearly hit me; I ______.
| A．might be killed | B．might have been killed |
| C．may be killed | D．may been killed |
“I called you yesterday. A woman answered, but I didn’t recognize her voice.” “Oh, it _____ my aunt Jean.”
| A．must be | B．must have been | C．might be | D．can have been |