根据对话内容，从方框内选择恰当的句子将对话补充完整。（选项中有两项是多余的）

A. What are they? B. Where did you go? C. What did you do there? D. What was the talk show about? E. How was the pollution caused? F. It's our duty to protect the environment. G. Would you like to help protect the environment?

A: Hello, Jack! I called you last night but you weren't in.

B: Oh, I went to the TV station of our city.

A: Really?

B: I took part in a talk show.

A:

B: It was about how to be a greener person.

A: Sounds great! It is very important for everyone to be a greener person, isn't it?

B: Yes.

A: What should we do to be a greener person?

B: We can obey the three R's.

A: The three R's?

B: Reduce, reuse and recycle.

A: Oh, I see. Ifs very kind of you to tell me so much.

B: It's my pleasure.