单选题 (Not until) my mother told me (the sad news) last night (I knew) that our neighbor (was killed) in a car accident the week before.
A. Not until B. the sad news
C. I knew D. was killed

【正确答案】 C
【答案解析】应改为did I know.将not until提到句首时,主句要用半倒装结构,正如此题。