◎ 题干
— Why do you look so worried?
— My MacBook Pro broke down and my paper________unfinished since.
[     ]
A. was left      
B. has left  
C. left    
D. has been left
◎ 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“— Why do you look so worried?— My MacBook Pro broke down and my paper________unfinished since.[ ]A. was leftB. has left C. leftD. has been left…”主要考查了你对  【现在完成时的被动语态】  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。