情态动词
用法: (1) can, must, may, should, could ... +
(2) 特殊:
从A、B、C、D四个选项中，选出可以填入空白处的最佳选项。
（1） --- May I go out to play now, Mum?
--- No, You must ____ your homework first.
A go B. goes C. going
（2） We should _______ a meeting this morning.
A. having B. have C. has
（3）She must _____ careful when she cooks dinner.
A. is B. are C. be
（4）--- Why do you ask Mike to do the difficult work?
--- Because he can ______ it very well. You do best in it.
A. does B. do C. doing
（5）The windows are dirty. They need ______________.
A. clean B. cleans C. cleaning D. to clean
（6）--- Can he _____ your bike？
--- Certainly. Here is the key.
A. used B. use C. use
（7） Marry is cooking dinner now. She can _____ very well.
A. cook B. cooks C. cooking
（8） Look！Mike is doing housework. He must _____ his socks before playing.
A. washing B. washed C. wash
(9) My hair is too long. I need __________ cut them.
A. cut B. cuts C. cutting D. to cut
(10) My hair is too long. They need ___________.
A. cut B. cuts C. cutting D. to cut
