This is a book 改为复数句

This is a book 改为复数句 this is a chinese book改为复数句 this is a book改为复数形式 Is this a book?的复数句 this is my book（改为复数句） Is this an English book?改为复数句 this is an English book 改为复数句 this is my book帮我改为复数句 IS this his book?改为复数句 This is my pencil.改为同义句 This is a pear.改为复数句 this is a tree 改为复数句 Is this a bus （改为复数句 this is a shirt改为复数句 this is a watch(改为复数句) this is a pen.改为复数句 This is a shirt .改为复数句 this is a pencil改为复数句 This is a butterfly改为复数句