把下面几个句子改为被动语态在线等谢谢~Wedon’toftenspeakEnglishathome.Theydidn’tcookmealsyesterday.Weshouldobeytherulesinourschool.ThegirlsoftensingEnglishsongsafterclass.Theycanmakethiskindofmachine

　　把下面几个句子改为被动语态在线等谢谢~

　　Wedon’toftenspeakEnglishathome.

　　Theydidn’tcookmealsyesterday.

　　Weshouldobeytherulesinourschool.

　　ThegirlsoftensingEnglishsongsafterclass.

　　Theycanmakethiskindofmachineinthefatory.Theoldmanbuiltanewhouseinfrontofthemountain.

　　Didyouleaveyourkeyonthedesk?

　　Hewillfinishhisnewbooknextmonth.

　　Theydidn’theldthesportsmeetingbecauseoftheheavyrain.

　　Theyneed20desks.

　　Mustwecleantheroom?