you must finish you homework______you are back at schoolA.after B.befor C.until D.if选哪个?给翻译一下back at school是返校的意思？有这种用法吗

You must finish your work a___ You must finish your homework （one） You must finish it ____(care) 为什么是you must finish doing your homework,而不是you must finish your homework? When you finish doing your homework ,you must c_____ it. 变被动语态：You must finish the work. You must finish yiour homework on time 改为祈使句 you must finish your homework first.否定句 Must I finish it now?No,you ___. you must finish at ------[little]most part of the work Must i finish the exercise this afternoon?Yes,you ______ Do you must try____work tomorrow?是to finish 还是finishing 反义疑问句you must finish it now,____________you? You must finish it __(care)Cats like chasing__(mouse) Before you go out you must finish the work.must换成haveto对吗? Lily,you must finish ___(write)your report beforLily,you must finish ___(write)your report before the meeting begins you must ___your homework on sunday.a.finish b.finished c.finishing d.to finish You must try your best () the work next week.A finish.B to finish.C finish.D finishes