Not until he walked into the classroom that he left his dictionary at home.
A. did he find
B. had he found
C. he had found
D. he found
网友回答
A. did he find
B. had he found
C. he had found
D. he found
解析：选A。考查倒装语序。此处not until置于句首, 主句应用倒装语序, 故首先排除C和D两项; 另外, 由句子时态是过去时可知此题选A。