—John has put forward ________ most challenging question for us to answer.—Yes,it really is.I have never heard ________ harder one.
We mustn’t waste anything; ______, we mustn’t waste our time.
— Look, it _____ be Jack who is at the gate of the library.It _____ be him. He has gone abroad.may; must B. must; mayn’t C. must; can’t D. can; mayn’t
She knows a lot about the film. She must have seen it before, ______ ?must she B. mustn’t she C. has she D. hasn’t she
Every morning she has to ______ her little daughter, then takes her to catch the early bus in a hurry.
I don’t think the watch will ______ much. It is ______ $30 at most.