问题补充:
I failed in the spoken examination last term and only then the importance of practicing speaking English.
A. I had realized
B. had I realized
C. I did realize
D. did I realize
答案:
A. I had realized
B. had I realized
C. I did realize
(答案→)D. did I realize
解析:本题考查倒装。首先由时间状语then确定时态为一般过去时,而时间状语由only引出放于句首,句子产生部分倒装,即助动词提前到主语之前,其他成分保持位置不变。