Read and act it out．(读一读，演一演)

A：Whose bag is it?

B：I don't know．Is it Lingling's?

A：No, Lingling's bag is red．But this one is blue．

B：Look, Sam is coming!Is it his?

A：Let's ask Sam．

A&B：Sam, is it yours?

C：Yes, it is mine．

A&B：Here you are．

C：Thank you!