.— John,you _____ go out to play until your homework __________ .—OK,Mum..Amust; finishes B.can’t; is finished C.can’t; has finished D.needn’t; finishes

问题描述:

.— John,you _____ go out to play until your homework __________ .—OK,Mum.
.Amust; finishes B.can’t; is finished C.can’t; has finished D.needn’t; finishes

C 约翰,你不能去外面玩直到作业完成

C
not until 直到……才……
因为是完成作业,所以用现在完成时态,has/have+动词的过去式
John.直到你完成作业才能去玩

选 B can’t; is finished homework,是被做完的,所以一定要用被动语态.这里只有 B 里的 is finished 是被动语态.C has finished 是现在完成时,不行.如果要用现在完成时,要说:until your homework has been finished...

排除a,d.选c.
应注意until的用法。
until和现在完成时有关。
until前是否定形式。