判断正误。对的写正确，错的写错误。

Which is my pencil case?

A: Excuse me, what are you looking for?

B: My pencil case. Where is it?

A: Is it in your desk?

B: No, it isn't. It's Lucy's.

A: Is it under your desk?

B: No, it isn't. It's Ann's.

A: Is it next to the chair?

B: Let me see. Err, no, it isn't. It's David's.