—Come in, please. Make yourself at home.—I'm glad you like it.A. Thanks. You have a nice place here.B. Oh, this picture is so beautiful!C. Thanks. What nice food you've prepared!D OK. Let me look around your new house.
31. Do you know when did the world _____?
30. The coal we use today should _____ plants and trees.
29. That's all for the party. Let's _____.
28. They ____ friends since they met in Shanghai ten years ago.
27. When he heard the news, his heart ______ very fast.