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.
