this is a ruler 改为复数

this is a ruler 改为复数 That's a ruler.对 a ruler 提问.Is this an apple?改为复数句子. lt is a ruler(改为复数） this is a ruler.改复数 This is a ruler 改为一般疑问句 This is a ruler改为一般疑问句 Is that a ruler?(改为复数句） ls this your ruler改为复数句 is this your ruler? 改为复数句 Are these her erasers?改为单数句 [紧急求助]This is a ruler.改为否定句 This is his ruler(改为复数句) That is my key(改为复数句) These are his brother Is it your ruler?改为复数句 That is ruler改为复数句 This is a book 改为复数句 This is a pear.改为复数句 this is a book改为复数形式 This is a dress.改为复数形式 this is a tree 改为复数句