this is my desk改成复数句

this is my desk改成复数句 This is my dress.改成复数句. This is my desk.的同义句 This is my backpack.改成复数形式 Whose toy is this?改成复数句 This is a desk 复数 This is my sister(变为复数句) This is my cousin.(改为复数句) this is my knife改复数句 That is a desk .(改成复数) this is my eraser.改成否定句 this is my ruler改成否定句 this is my ring改成同义句 This is my ball.改成同义句 英语句的复数形式What is this?It is a desk.改为复数形式 this is my pen pal改成复数形式 this boy is my goog frierd改成复数形式 This is my cup 改成复数句子怎么改啊