Is this a ruler?怎么改成否定句

Is this a ruler?怎么改成否定句 this is my ruler改成否定句 This is a ruler(对a ruler提问) ----- -----this? This is a green ruler 对a green ruler 提问.怎么提? This is a ruler怎么改一般疑问句 This is a red ruler 用a red ruler 提问 This is my ruler中的my ruler怎么提问? this ruler is for gao shan改成同义句 This is a ruler 改为一般疑问句 This is a ruler改为一般疑问句 Is this a ruler.(做否定回答) is,a,this,red,ruler 连成句 this is a ruler 改为复数 this ruler is-----?a:myb:mine this is a ruler.改复数 翻译：and this is a ruler Whis is this?回答A：This is ruler.B：It is a ruler. Is this a ruler.---Yes,this is.（改错）