Is that boy your brother 改复数形势

Is that boy your brother 改复数形势 Is that boy your brother?答句 that boy is good.改复数 is that your brother 改为复数 it that your brother 改复数怎么改 that(复数) this(复数) brother(对应词) is(复数) boy(复数) I(形 is that gril your friend 改复数 brother,tall,that,your,is,boy,连词成句 Is that boy your brother? ___ We look the same . your boy brother is that连词成句 Is that your brother?怎么改为复数句 Is that your brother?