问题补充:
Not until I began to work how much time I had wasted.
A. didn I realize
B. did I realize
C. I didn realize
D. I realize
答案:
A. didn I realize
(答案→)B. did I realize
C. I didn realize
D. I realize
解析:句意,直到我开始工作,我才意识到自己已经浪费了很多时间。not until,引导的时间状语从句置于句首,从句要用陈述语序,主句要用倒装语序,故选B。