Question

【题目】Many students didn’t realize the importance of study_____they left school.

A. when B. until

C. as D. after

Answer 1

【答案】B

【解析】句意：许多学生直到辍学后才认识到学习的重要性。when当……时候；until直到；as当……时候；after在……之后。not……until……“直到…….才……”,故选B。