This is (he)schoolbag.Is (he)your friend?

Is this your schoolbag? Is this your friend 肯定回答是什么?Is he your friend?还有 Is David yo Is he your friend yes___. （）he your friend yes,he is. 是is this schoolbag your还是is this schoolbag yours is he your friend,为什么用is? ( ) is your friend?He is a policman. Is he your friend?改为复数 he your is friend 连词成句 Is this?your friend is he .friend.your.no.isn’t.this.is.怎么连词成句啊? 是Is Jim your friend or her friend还是Is Jim your friend and he