. The government has to close those small factories to prevent the water of the river ______.
| A．polluting | B．from polluting | C．being polluted | D．polluted |
.When we reached the station, the train had still not arrived; so we ______.
a. needed not to hurry b. needn’t have hurried
c. need not to have hurried d. didn’t need to hurry
.The boy told his father that he would rather ______ an astronaut.
a. become b. to become c. becoming d. became
.He is really incompetent! The letter ______ yesterday.
a. should be finished typing b. must be finished typing
c.must have finished typing d. should have been finished typing
You ______ the examination again since you had already passed it.
a. needn’t have taken b. didn’t need to take c. needn’t take d. mustn’t take
“I wonder why they’re late.” “They ______ the train.”
a. can have missed b. could miss c. may have missed d. might miss