什么时候用be动词?比如是we are cleaning our room还是we clean our room?

We must keep our room clean.Dirt ... Shall we ____(keep) our room clean? Let's clean our room,shall we?和Let us clean our room,will yo We should keep our room clean 改被动语态 we+keep+our+room+clean是什么句式结构? our room must be kept clean.中的keep不是系动词么,怎么用被动态 We are cleaning our classroom对cleaning our classroom提问 we have just been told that we need to clean our room first we've just been told that we need to clean our room first an my sister and i are cleaning our room对划线部分提问cleaning our roo We like our room.(变为一般疑问句 room,we,after,clean,school,our.（组词成句）对的采纳!