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

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 realized

答案：

A. didn’t I realize

(答案→)B. did I realize

C. I didn’t realize

D. I realized

解析：本题考查倒装结构。not until引导状语从句位于句首时，主句要倒装，故选B。句意：直到我开始工作我才意识到我已经浪费了多少时间。