they have swpet the filoor and cleaned the window.(改为否定句） th

they have swpet the filoor and cleaned the window.(改为否定句） th I have to close the window改为否定句 There is a table and a chair near the window.(改为否定句） please open the window.改为否定句 Please close the window改为否定句 please open the window. 改为否定句 Open the window ,please.改为否定句 The science teacher cleaned the bus（改为否定句） The science teach Open the window,please（改为否定句） They have cleaned the room already.改为一般疑问句 the students have cleaned their classroom already.改否定句 They have already finished the work.如何改为否定句