The collapse of the World Trade Centre has put US economy in a difficult ___________.
| A．occasion | B．case | C．situation | D．background |
You _________leave the window open. It’s so cold.
| A．mustn’t |
| B．needn’t |
| C．mightn’t |
| D．won’t |
Facts prove that the world’s economic development is not a win-lose game but one in which all ________ be winners.
| A．can |
| B．shall |
| C．must |
| D．would |
When we lived in that village, we ________ often play together in the river there.
| A．might |
| B．should |
| C．could |
| D．would |
—Isn’t that your boss over there?
—No, it ________ be him. I’m sure he is in the office now.
| A．can’t |
| B．must not |
| C．won’t |
| D．may not |
How ________ you say that you really understand the whole text if you have covered only part of it?
| A．can |
| B．must |
| C．need |
| D．may |