A. it's not a good manner in public places. B. It's also very dangerous.

     C. Let me take a photo for you.              D. I think he is taking photos.   

E. It's the longest wall in the world. F. I want to take better photos.

Mary：Wow, look at the Great Wall. It's really great.

Tracy：Yes,

Mary：Oh, look at that man over there. What is he doing?

Tracy：But he is climbing up on a tree.

Mary：That's a bad manner.

Tracy：Yes, we should tell him not to climb up on that tree. Let's go.

Mary：Excuse me, sir.

Man：Yes?

Tracy：What are you doing up there?

Man：.

Tracy：But it's not safe to climb up on the tree and .

Man：Right, thank you very much. I shouldn't do that.

Mary and Tracy：OK. Smile!