根据对话内容，从下面方框中选出恰当的句子补全对话。

A. We looked so excited in the photos. B. And then she would fall asleep in class. C. Long time no see! D. Isn't that Sarah over there? E. I can't believe it's been five years.

Paul: Hello, Helen .

Helen: Hello, Paul. It is nice to see you and so many old friends.

Paul: So itis.

Helen: You are right. It's really a long time。

Paul: Did you see the old photos?

Helen: I sure did.

Paul: And 'those are some great memories.

Helen: Hey!

Paul: Yes; it is. I remember she used to stay up all night studying.

Helen:

Paul: Yes: She was the only one left in the class when she woke up.

Helen: That was 'really funny.