Who cleaned the classroom is a question( )we should answer

Who cleaned the classroom is a question( )we should answer ---Who cleaned the classroom yesterday?---John ().A.cleaned Who cleaned the classroom?怎么回答 Who cleaned the classroom?改为被动语态 who cleaned the classroom yesterday - dick _____ . 问We should make the school ()?a.cleaned,b.cleaning we should Keep our classroom ---A.cleaned B.clean C.cleaning The classroom is cleaned by the students. the question is so easy that we can answer it. A:who is singing in the classroom reply,answer Who can ＿the question? who know the answer ( ) this question ?