I don't believe him. He _____ be serious.A. can'tB. mustn't
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No one _____ that to his faceA. dare sayB. dare to say
Since she is angry, we _____ as well leave her alone.A. mightB. should
Since they aren't answering the call, they _____ have left.A. mayB. must
I failed to get in touch with him before he left. I _____ have phoned.A. shouldB. would