【题目】Only when the teacher walked into the classroom ________ that she had left the speech note at home.
A. she realized B. has she realized
C. she has realized D. did she realize
在线课程【答案】D
【解析】
考查部分倒装。句意：只有当老师进入教室的时候她才意识到她把演讲笔记忘在家里了。此处only+状语位于句子开头，句子用部分倒装；when引导的时间状语从句的时态是一般过去时态，所以这里主句也用一般过去时态，因为这两个动作几乎是同时发生的。故答案为D。