Is it a bus?的复数句

Is it a bus?的复数句 is it a bus改为复数形式 this is a bus.【变为复数句】 Is this a bus （改为复数句 --What is this?--It is a bus.改为复数是什么? It's a new bus.改为复数句 that is a bus.(变为复数句） Is that a bus?(改为复数句） this is a bus.把它改为复数句 it is a mouse改为复数句 It is a calf(改复数句) it is a strawberry 改为复数句