It was not until the entrance exams were in sight that that I had so many books to cover a

问题补充：

It was not until the entrance exams were in sight that that I had so many books to cover and so many exercises to finish.

A. I realized

B. did I realize

C. had I realized

D. I had realized

答案：

(答案→)A. I realized

B. did I realize

C. had I realized

D. I had realized

解析：此句是I didn realize that I had so many books to cover and so many exercises to finish until the entrance exams were in sight．的强调句。not until…in sight位于强调结构中，realize就变成肯定，用过去时。