Question

— 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

Answer 1

　　　C　

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。