题目内容：

what are you doing here,peter?You are____ to be at home .doing your homework.
A used B supposed C known D added 详细解答一下

优质解答

大意是 问petter 你在干嘛呢～你不是应该在家做作业吗?
A used to be 被用作
B suppose to be 应该是
c known to be 为...所知
D added to be 加入
therefore ,the answer should be B.