— Were you worried about him last night?
— Yes. It was .
A. until he returned that I went to bed
B. until be returned that l slept well
C. not until he returned that I went to bed
D. not until did he return that I went to sleep
网友回答
A. until he returned that I went to bed
B. until be returned that l slept well
(答案→)C. not until he returned that I went to bed
D. not until did he return that I went to sleep
解析：此处强调句型，强调是until从句，如复原应为I didn't go to bed until he returned.这个句型变为强调句型应注意，主句中的not在强调句中移至until之前。