Every means _____ prevent the water from _____.
| A．are used to; polluting | B．will be used to; polluting |
| C．is used to; polluted | D．is used to; being polluted |
They considereda computer, which was considereda great help in their work．
| A．to buy; to be | B．buying; being | C．to buy; being | D．buying; to be |
The number of people invited __________ fifty, but a number of them _______ absent for different reasons.
| A．were… was | B．was… was |
| C．was… were | D．were… were |
The place was flooded ________ it had been raining for several weeks.
| A．because | B．because of | C．ever since | D．as a result of |
Mr. Smith has been here for only a few days, so he hasn’t left a deep impression _____ us.
| A．on | B．with | C．about | D．for |
I don’t think she will come to the meeting on time,?
| A．do I | B．do you | C．will she | D．won’t she |