• “Look at these tracks.It _______ be a wolf.” “Don’t

• “Look at these tracks.It _______ be a wolf.” “Don’t be so sure.I think it _______ be a fox.”
• A.must; could B.may; might
• C.need; must D.could; need
• “Is there a flight to London this evening?” “There _______ be.I’ll phone the airport and find it out.”
• A.must B.might
• C.would D.can
• The missing children haven’t been found yet.Something terrible ________ to them.
• A.may happen B.should have happened
• C.must happen D.might have happened
• They often go to the restaurants for meals.They _____ be very poor.
• A.mustn’t B.can’t
• C.may not D.needn’t
• The postman _______ be at the door.It’s only six o’clock.
• A.mustn’t B.can’t C.won’t D.needn’t
• You _____ be right,but I don’t think you are.
• A.can B.could C.must D.should
• —I don’t really like James.Why did you invite him?
• —Don’t worry.He_____come.He said he wasn’t certain what his plans were.
• A.must not B.need not C.would not D.might not
• “Do you think he is lazy?” “I _____ so once,but I don’t now.”
• A.may have thought
• B.can have thought
• C.may think
• D.might think
• Their answers are exactly the same — one of them ______ from the other.
• A.must copy B.must have copied
• C.should copy D.should have copied
• “I called you yesterday.A woman answered,but I didn’t recognize her voice.” “Oh,it _____ my aunt Jean.”
• A.must be B.must have been
• C.might be D.can have been
• “I heard they went skiing in the mountains last winter.”
• “It ____ true because there was little snow there.”
• A.may not be B.won’t be
• C.couldn’t be D.mustn’t be