A: I left a suitcase on the train to London the other day.

B: Can you describe it， sir?

A. MALL: It's a small blue case and it's got a zip. There's a label on the handle with my name and address on it.

B: Is this case yours?

A: No， that's not mine.

B: What about this one? This one's got a label.

A: Let me see it.

B: What's your name and address?

A: David Hall， 83， Bridge Street.

B: That's right. D.N. Hall， 83， Bridge Street.

A: Three pounds fifty pence，please.

B: Here you are.

A: Thank you.

B: Key!

A: What's matter?

B: This case doesn't belong to me!

You've given me the wrong case!