根据对话中提到的动物的先后顺序给图片标上序号。
A: Look at the panda. Is it thin?
B: No, it isn't. It's fat. And the tiger is big.
A: Look at the giraffe. Is it tall?
B: Yes, it is. And I'm short.
A: Look at the bird.
B: It's little.
A: What's that?
B: Oh, it's a snake. It's very long.