Tom:Hi,Jack.

Jack:Oh,Tom,Nice to meet you!

Jack:Oh,hello!I'm afraid we have seen each other before,do you remember me?

Lily:Hr,I'm afraid I forget it.I'm sorry,but when was that happened?

Lily:Oh,I think about it.You are that hummor brother.Glad to see you again.

Tom:So you two knew each other before.It's so good.

Jack:I really don't know that you two are sister and brother.