Please don’t stand up in class you .A. until ; are told toB. when ; are toldC. after ; we

问题补充：

Please don’t stand up in class you .

A. until ; are told to

B. when ; are told

C. after ; were told

D. before ; were told to

答案：

(答案→)A. until ; are told to

B. when ; are told

C. after ; were told

D. before ; were told to

解析：句意：在课堂上请到允许你时再站立。Not···until直到……才，是一固定句型；主句使用一般现在时，故时间从句也用一般现在时。Tell sb to do sth告诉某人做某事，改为被动语态后不可丢掉不懂事标记to。所以选A。