Not until I began to work how much time I had wasted. A. didn’t I realizeB. did I realiz

问题补充：

Not until I began to work how much time I had wasted.

A. didn’t I realize

B. did I realize

C. I didn’t realize

D. I realize

答案：

A. didn’t I realize

(答案→)B. did I realize

C. I didn’t realize

D. I realize

解析： not until引导的状语置于句首时，主句用部分倒装。