caused the accident is still a complete mystery.A. WhatB. ThatC. HowD. Where

发布时间：2020-08-16 18:36:16

     caused the accident is still a plete mystery.
A. What
B. That
C. How
D. Where

网友回答

(答案→)A. What
B. That
C. How
D. Where
解析：本题考查名词性从句。从句中动词caused缺少主语，故用what作从句的主语。选A。
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