Many students didn’t realize the importance of study they left school.A. whenB. untilC. a

问题补充：

Many students didn’t realize the importance of study they left school.

A. when

B. until

C. after

D. unless

答案：

A. when

(答案→)B. until

C. after

D. unless

解析：此题考查对语句的理解，及重点句型结构，not…until