改正错误；Who‘s that ？It‘s a bird

What's that? It's a bird.

What‘s that ？It‘s a bird

正确的我想应该是 ：What is that? It is a bird.

我觉得有两种改法
一个是
who‘s that ？ That‘s a bird
还有一种是
who‘s it ？ It‘s a bird
好象学英语的时候有前后要一致吧
不知道对不对

What's that? It's a bird

What's that?
It's a bird.