Not until the train pulled into the station that his suitcase was gone.
A. had he found
B. did he find
C. he had found
D. he found
网友回答
A. had he found
(答案→)B. did he find
C. he had found
D. he found
解析：考查倒装句：句意：知道火车驶进站，他在发现箱子没有了。Not until是否定意义的词组，放在句首的时候，句子用部分倒装，因为是在火车驶进站后，他才发现箱子没有了，用一般过去式，助动词did提到主语前面，选B。