. Professor Smith and Professor Brown will _____ in giving the class lectures.
| A．exchange | B．alter | C．shift | D．alternate |
Martin hasn't been in touch with me for ages. He ________ my new cellphone number.
| A．needn't get | B．mustn't get |
| C．can't get | D．shouldn't have got |
If you won't do as I tell you, you ________ get the chance to be promoted because the competition is just too fierce.
| A．couldn't | B．mustn't |
| C．shouldn't | D．shan't |
We ________ have hurried all the way to the airport — the flight was called off because of the foggy weather.
| A．mustn't | B．couldn't |
| C．needn't | D．wouldn't |
—Mike, I can't find my watch anywhere.
—You ________ it while working out.
| A．may have lost | B．could have lost |
| C．would have lost | D．should have lost |
—Where did you get this book?
—I picked it up from a secondhand bookshop if you ________ know.
| A．must | B．will |
| C．can | D．shall |