【答案解析】[听力原文]18-21
W: Hi, Simon. I won't be in class today. Fm sick as a dog.
M: Who is this?
W: It's Mary. No wonder you don't recognize my voice because I'm so sick.
M: Right. I didn't even know it was you. What's going on?
W: I don't know. I must have caught a cold. I have such a bad stuffy nose, I can hardly breathe. And I ache all over.
M: Well, sounds like a respiratory infection, or maybe the flu. What are you doing for it?
W: Wall, I'm staying in bed with a heating pad and lots of vitamin C.
M: That's a good idea. Whatever you have, it's probably contagious. Do you think you need to see a doctor?
W: well, I would rather get an injection for the pain in my neck, or some nontraditional medicine.
M: Don't forget to drink lots of water.
W: Thanks for the advice. Could you call me later with the assignment? I don't want to fall behind in class.
M: Sure. Take care. Talk to you later.
单选题
What is the probable relationship between the two speakers?