She has cleaned the room.这句中的has起到什么作用?

She has cleaned the classroom.（The teacher knows） She has cleaned the room.这句中的has起到什么作用? she is drinking some milk he has cleaned the room 换成被动语态she is drinking some milk he has cleaned the room这两条变成 被动语态 he has cleaned the classroom 对 cleaned the classroom提问 she_____the blackboard before the teacher arrived.A,had cleaned B,cleaned C,has cleaned D,cleans She has already cleand the kitchen.（改为否定句） She hasn't cleaned the kitchen yet.我知道答案,但是我想知道是为什么 句型：she cleaned the room after breakfast.对cleaned the room提问（改成疑问句 快**********The windows are so bright,who ______them?_______上应该填have cleaned has cleaned还是cleaned?请讲出为什么 The room__when I arrived.A.had cleaned B.is clean C.has been cleaned D.was being cleaned 初中英语 现在完成时 的问题the room is so clean who has cleaned it 用cleaned行不行 the room has been cleaned by tom 对tom提问____ ____the room____ cleaned ____ cleaned the She cleaned the room yesterday.变为否定句 (she) cleaned the room after breakfast.对括号提问 she has the wach. what’s your father doing now?he()the room a.cleaned b.cleans c.has cleaned d.is cleaning how clean the window is.yes.it---just now.为什么用has been cleaned不用was cleaned How clean the bedroom is!Yes,I amsure that someone___it.A.cleans B.cleaned C.has cleaned D.is cleaning