He ___ without saying good-bye to them, for he always has good manners.
| A．mustn’t have left | B．may not have left | C．shouldn’t have left | D．can’t have left |
We saw a ________ big snake in the grass yesterday, which ________ all of us to death.
A. frightened; frightened C. frightened; frightening
C. frightening; frightened D. frightening; frightening
— Tom, could you go to the supermarket with me?
— I’d like to, but my homework ______ and I have to hand it in tomorrow.
| A．wasn’t finished | B．won’t be finished |
| C．hasn’t been finished | D．hadn’t been finished |
Special attention should be paid to ________ forests from fires in winter.
| A．protected | B．protecting | C．protects | D．protect |
________ is no doubt _______ Mo Yan, this year’s Nobel Prize winner in Literature, ever did so much on his way to success.
| A．It; whether | B．There; if |
| C．There; whether | D．There; that |
The fields where crops used to be grown ________ for building now.
| A．have used | B．have been used |
| C．are being used | D．are used |