◎ 题干
when you want to go into the room,you should _________the door.
[     ]
A.knock on    
B.knocking on        
C.knocks at    
D.to knock at
◎ 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“when you want to go into the room,you should _________the door.[ ]A.knock onB.knocking on C.knocks at D.to knock at…”主要考查了你对  【动词短语】  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。