______ caused the accident is still a complete mystery.

admin2009-07-15 71

问题 ______ caused the accident is still a complete mystery.

选项 A、How
B、That
C、Where
D、What

答案D

解析本题中要填的词应在从句中作主语，同时引导主语从句。既在从句中担任名词性成分又引导从句的只能是关系代词what；that是从属连词，不在从句中担任成分。其它两个是连接副词，主要作句子的状语。正确答案为[D]。

转载请注明原文地址:https://www.kaotiyun.com/show/jJyd777K

公共英语二级笔试

相关试题推荐

随机试题

最新回复(0)