When and why he came here ________ yet. A．is not known B．are not known C．has not known D．have not b...
2023-02-01 00:40:36 208次 2010届三轮语法回扣专项训练（名词性从句） 单项填空 反馈错误 加入收藏 正确率 : 100%
题目内容：
When and why he came here ________
yet.
|
A．is not known
|
B．are not known
|
C．has not known
|
D．have not bee
|
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