Not until he promised to return it to me as soon as possible my electronic dictionary to my classmate.
A. had I lent
B. did I lend
C. I had lent
D. I lent
网友回答
A. had I lent
(答案→)B. did I lend
C. I had lent
D. I lent
解析：考查倒装句：句意：直到他答应尽快归还电子词典，我才答应把它借给我的同学。Not until放在句首时，主句要部分倒装，助动词提到主语前面，因为两个动作是同时发生，用一般过去时，所以选B。