our room must be kept clean.中的keep不是系动词么,怎么用被动态keep用被动态是因为our room 提前了是吧

Our room must ＿＿clean.A.keepB.be keptC.to be kept D.to keep Our room must ___ clean.A.keep B.be kept C.to be D.kept our room must be kept clean.中的keep不是系动词么,怎么用被动态keep用被动态是因为our room 提前了是吧 there must be someone in the room _(be)there She must be in the room.的意思 we must (be)quiet in the reading room. the room must be kept wet.变成被动语态! 什么时候用be动词?比如是we are cleaning our room还是we clean our room? They must be in the reading-room,_______ _______[They must be in the reading-room,_______ _______[反义疑问句] Tom must be in his room.(改为否定句)Tom ___ ___ in his room. our,neighborhood,visiting,there,be,someone,homes,the,in,must Best love my sweet baby forever,our must be I think (it) must be our monitor.为什么填it? We must try our best to be green _______.(consume) We must try our best to be green _______.(consume) Our homework must be finished first（改为主动语态） our must in her be teacher office连词成句快一些 our country must be able to keep pace technologically