It’s strange that they ________ without saying goodbye to us.

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We needn't ________ preparations for the meeting. Mr. Zhang called it off.

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—There were already five people in the ear, but they still managed to give me a lift.

—It ________ a comfortable trip.

[　　]

A．can't be

B．shouldn't be

C．mustn't have been

D．couldn't have been

Powell ________ yet, otherwise he would have telephoned me.

[　　]

A．mustn't have arrived

B．shouldn't have arrived

C．can't have arrived

D．need not have arrived

I didn't hear the bell ring, I ________ asleep.

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One ought ________ for what one hasn't done.

[　　]

—________ Jack be here now?

—He ________ be here, but I'm not too sure.

[　　]

—________ I go home now, sir?

—No, you ________. You should finish the composition first.

[　　]

Don't believe him. What he said ________ be true.

[　　]

Nancy ________ out alone at night.

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