It was____his mother came in____to prepare his lessons.A.not until ; did the boy begin B.until ;that the boy began C.until ;did the boy beginD.not until ;that the boy began答案选D为什么不能选A呢
问题描述：
It was____his mother came in____to prepare his lessons.
A.not until ; did the boy begin
B.until ;that the boy began
C.until ;did the boy begin
D.not until ;that the boy began答案选D为什么不能选A呢
答
我觉得吧：不是有个用法是It's not until...that.吗？然后后面那个空填A的话，不就是一个疑问句了，后面得填一个陈诉句，如果A把did去了，就可以选．
答
强调句型.it is/was ...that...固定搭配