It ____ last night, for the ground is wet now.
| A．might not have rained | B．must have rained | C．couldn't have rained | D．rained |
Since everyone would like to find an apartment near the university, there are very few ____ apartments in the area.
| A．free | B．vacant | C．empty | D．reserved |
The U.S.A. made a lot of excuses in an attempt to make war on Iran. However, its ____ purpose lay in the plentiful oil there.
A. incredible B. fundamental C. flexible D. identical
---You ought to have warned him of the danger!
--- ____! But he wouldn’t listen!
| A．So did I | B．So ought you | C．So I did | D．So I have |
The flood is believed ____ more than 50 people and made thousands homeless, ____ it perhaps the most destroying flood in history in the area.
| A．killing; to make | B．to have killed; making |
| C．to have killed; having made | D．having killed; making |
How can you expect to learn anything ____ you devote all your energies to playing computer games?
| A．in case | B．while | C．when | D．unless |