听力原文：W: James, what's your opinion about nuclear energy？
M: Nuclear energy？ That's quite an issue! I actually have some pretty strong viewpoints regarding nuclear energy. Are you interested in hearing them？
W: Yes.
M: Well, in my opinion, nuclear energy is our best hope for the future.
W: But don't you think it poses a threat to the safety of the population？
M: Not really. As I see it, nuclear reactors are a clean and safe source of electricity.
W: Well, if you ask me, people don't realize how dangerous radiation can be.
M: The thing to keep in mind is that our oil and gas resources are limited.
W: Let me say one more thing.
M: Okay.
W: I'd just like to point out that I think too many accidents are happening at nuclear power plants all over the country.
M: You know honey, we could probably go on talking about this forever and never come to an agreement.
W: You are probably right dear. I guess we just don't see eye to eye when it comes to nuclear energy.
M: I guess not.
(20)

A. Doctor and patient.
B. Husband and wife.
C. Teacher and student.
D. Tourist and guide.