When asked to explain _____ he did to make his students so fascinated with his lessons, the teacher paused and thought deeply.
| A．what was it that | B．that what it was | C．what it was that | D．what was it |
It’s cold in here. We must have the fire day and night.
| A．burn | B．burns | C．burnt | D．burning |
--- Who’s the man giving the speech?
--- Well, if you ____ know, his name is Lyric.
| A．may | B．can | C．shall | D．must |
-----Is it good to look up every new word when I come across it in reading?
-----No. You _______ because you are likely to guess the meaning from the context.
| A．can’t | B．mustn’t | C．don’t have to | D．shouldn’t |
—What do you think we can do for our aged parents？
—You do anything except that you visit them as often as possible.
don’t have to B. oughtn’t to C. mustn’t D. shouldn’t
---May I remind you that Mr. White is waiting outside, Mrs. Green?
---Oh, I _________ all about it.
| A．forget | B．had forgotten | C．forgot | D．was forgetting |