练习1. A computer ______ think for itself; it must be told what to do. A. can’t B. couldn’t C. may not D. might not2.She has to answer for what she has done,____? A.doesn’t she B.hasn’t she C.has she D.does she3.You ___to the meeting this afternoon if you have something important to do. A.needn’t B.needn’t to come C.needn’t come D.don’t need come4.Look! what you have done. You ___be more careful. A.may B.should C.would D.had to5.---Shall I tell John about it? ---No,you ____ .I’ve told him already. A.needn’t B.wouldn’t C.mustn’t D.shouldn’t6.She doesn’t answer the doorbell. She ___ be asleep. A.might B.ought to C.should D.must have 7.___he ___a famous doctor at that time? He was so young then. A.Can;be B.Must; be C.Can;have been D.Must;have been8.They ___ the plane,or perhaps they have been prevented from coming for some reasons.A.Can have lost B.may have lostC.can have missed .D.may have missed9. Johnny, you ______ play with the knife, you ______ hurt yourself. A. won’t ; can’t B. mustn’t ; may C. shouldn’t ; must D. can’t ; shouldn’t10.I can’t find Mary anywhere.She must ___ her homework upstairs. A.do B.have done C.be doing D.have been done11.He ___ if he works hard for the people. A.shall praise B.shall be praised C.will praise D.will be praised12.Did he need ___ then? A.leave B.leaving C.left D.to leave13.---Oh,I’ve missed a good chance. ---Yes, you ___ the job when it was ___. A. should have taken; offered B. should take ;offered C. might have taken; offering D. had taken ;offered14.---She must have gone back to the valley. ---___ she ____.The entrance to it was nowhere to be found.A.No;mustn’t B.Yes;mightC.Yes;could D.No;couldn’t15.The professor gave orders that the ...
