You ______ your assignment before you watch TV.A.are doingB.are to be doingC.are to doD.do
问题描述：
You ______ your assignment before you watch TV.A.are doingB.are to be doingC.are to doD.do
答
C
分析：be to 表示将要做某事,客观安排或受人指示而做某事
翻译：在你看电视之前你要先完成你的作业