◎ 题干
Many questions have been answered by John. He must have previewed the lessons last night, _____ he?  
[     ]
A. needn't          
B. hasn't          
C. mustn't         
D. didn't
◎ 答案
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◎ 解析
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◎ 知识点
    根据魔方格专家分析,试题“Many questions have been answered by John. He must have previewed the lessons last night, _____ he? [ ]A. needn'tB. hasn't C. mustn'tD. didn't…”主要考查了你对  【助动词】  等知识点的理解和应用能力。关于这些知识点的“档案”,你可以点击相应的链接进行查看和学习。