问题补充:
Not until he walked into the classroomthat he left his dictionary at home.
A. did he find
B. had he found
C. he had found
D. he found
答案:
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。