After_was about ten minutes,the teacher gave the students the correct answer to the question....

题目

After_was about ten minutes,the teacher gave the students the correct answer to the question....
After_was about ten minutes,the teacher gave the students the correct answer to the question.
a.that b.it c.which d.what
这是定语从句,还是宾语从句缺主语?2为何不能it做行式主语?

答案

1 这是宾语从句缺主语,作after的介词宾语,整个前面分句作状语
2 不能用it,很简单后面的真正的主语在哪里呢?一般来说it是形式主语,都用于句型It is ...that/to do/doing 这样的结构
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