Question

Not until he left his home _____ to know how important the family was for him.

A．did he begin

B．had he begun

C．he began

D．he has begun

Answer 1

A

试题分析：句意：直到他离开家，他才意识到家庭对于他来说是多么的重要。这里not until放在句首句子，这里的主句用部分倒装。根据主句的谓语动词用的是过去式可知这里空格处也应该用过去式，故选A。
点评：本题难度适中。倒装句是高中阶段必须掌握的语法项目，它分为部分到装和全部倒装，情况复杂，需要考生熟记它们的用法。
即学即练：—How was the weather then?
—Hardly_____off the plane，when it started to rain.
A.I had stepped                 B.had I stepped
C.I stepped                      D.did I step
解析：B。hardly, seldom等否定副词位于句首作状语时，后面要用部分倒装，再由句意可知，选B。