Not until I dropped off from school how much time I had wasted.
A. didn't I realize
B. I realized
C. I didn't realize
D. did I realize
网友回答
A. didn't I realize
B. I realized
C. I didn't realize
(答案→)D. did I realize
解析：考查倒装句：句意：直到我在学校下降了，我才意识到浪费了多少时间。Not until引导时间状语从句，放在句首的时候，主句用部分倒装，因为前面有not，主句部分的谓语是肯定的，选D。