问题补充:
Not until I began to work how much time I had wasted.
A. didn’t realize
B. did I realize
C. I didn’t realize
D. I realized
答案:
A. didn’t realize
(答案→)B. did I realize
C. I didn’t realize
D. I realized
解析:此题考查的是否定词放在句首,使用部分倒装,助动词往前提。not until放在句首从句不倒装,主句倒装,然后根据时态选B