“When did he leave the classroom?” “He left you turned back to write on the blackboard.”A

问题补充：

“When did he leave the classroom?” “He left you turned back to write on the blackboard.”

A. the time

B. the moment

C. until

D. since

答案：

A. the time

(答案→)B. the moment

C. until

D. since

解析：the moment 用作连词，意为“一……就……”，相当于 as soon as。类似地，the minute, the instant 也可用作连词，表示“一……就……”的意思。