根据对话内容，在下面空白处填入适当的短语或句子，使对话意思完整通顺。

A: Good Morning!

B: Good Morning! My name is David. ?

A: I'm Lisa.

B: Is this your schoolbag?

A: No, mine is black. I think .

B: Hi, Frank. Is this your schoolbag?

A: Yes, thank you, David. ?

B: It's a watch.

A: ?

B: W-A-T-C-H.

A: .

B: You are welcome.