A．氮气     B．二氧化碳     C．氧气     D．水蒸气  E．氖气

Brian：Hi, Cindy.____

Cindy：Hi, Brian. It is nice to see you and so many old classmates.

Brian：So it is.____

Cindy：You're right.  It's really a long time.

Brian：Did you see the old photos on the wall?

Cindy：I sure did.____

Brian：But those are some great memories.

Cindy：Hey ！____

Brian：Yes, it is. I remember he used to stay up all night studying.

Cindy：____

Brian：Yes. He was the only one left in the class when he woke up.

Cindy：That was really funny.

A. And then he would fall asleep in class.

B. Long time no see!

C. Who took these photos?

D. Isn't that John over there?

E. We looked so funny in them.

F.I can't believe it's been ten years.

G. Did he use to be short ?