they must dust the room变成一般疑问句

they must dust the room变成一般疑问句 they must dust the room Must they dust the room肯定回答 must they dust the room?的否定回答是什么? 把They often clen the room(变成一般疑问句) They have cleaned the room already.改为一般疑问句 They have a table in the room改为一般疑问句 They must go home now. 变成一般疑问句、特殊疑问句、否定句 they must go home now 变成一般疑问句和特殊疑问句 they can stop the wind.变成一般疑问句 they can stop the wind .变成一般疑问句 I must help Tom clean the room.改为一般疑问句,并作肯定回答