听力原文：W: So, you'll be getting dressed up later--before you go to the BBC television studios. M: Yes, but to tell you the truth, Mary, I prefer working in radio. W: You prefer radio? M: That's right. You can dress down in a radio studio. W: What do you mean? M: You can dress down. You can wear something casual. There's no need to get dressed up. W: Well, I always try to make an effort to look smart! M: Yes, of course, you always look fantastic, Mary. But you don't have to dress up for radio. The audience can't see you. W: Ah, I see what you mean. In TV the audience can see you, so you have to look your best. M: Exactly. You have to dress up. You put on something smart so you look the part. W: Yes. I suppose if you're on TV, you have to look like a TV presenter you have to be dressed right. M: But in radio, the listeners can't see you so we can dress down if we want to. W: Yes. That's why I sometimes wear jeans to work. M: Exactly. On radio, I can take off my tie! I can even take off my shoes! W: I don't think so! You don't have to wear your tie--you can take that off if you want to, but please don't take off your shoes! (20)