Some researchers believe that there is no doubt _____ a cure for AIDS will be found.
A. which B. that C. what D. whether
Use the umbrella to ______ yourself from the rain.
A. prevent B. keep C. save D. protect
____ for a long time, but he managed to catch up with his classmates at last.
A. Having been ill B. Being ill C. He was ill D. Though ill
We mustn’t waste anything; ______, we mustn’t waste our time.
A. after all B. in all C. above all D. at all
— Look, it _____ be Jack who is at the gate of the library.
— It _____ be him. He has gone abroad.
A. 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, ______ ?
A. must she B. mustn’t she C. has she D. hasn’t she
