David: Where are we going?
Tim: We are going to the dinosaur museum.
David: Oh, yeah! That's great. I can't wait to go.
Museum interpreter: Here are some very old dinosaurs. This is stegosaurus （剑龙） .
Tim: Wow! Look at that. It looks like daggers on its back.
David: That's great! I will take photos with it. 
Museum interpreter: Boys! This is a museum. Be quiet and listen carefully please. 
Tim and David : Oh, I'm sorry