补全对话, 每空一句。

A: Hey, Frank!

B: Pretty good.

A: Did you have fun last weekend?

B:  I went to the old people's house with my friends and had a good time.

A: Wow! What did you do there?

B: We helped the old clean their houses and chat ted with them. How about you?

A: I just read a science magazine.

B: Oh, really?

A: Hmm……it is about the main causes of smog(雾霾) and ways to beat it.

B: Great! But

A: We can live a greener life by using cleaner energy to solve the problem, I think.

B: You do?

A: Yes, natural gas is a good choice. By the way,  

B: It's 7: 45 now.

A: Oh, God. Hurry up, or we'll be late.

B: OK.