听力原文：W: Where do you think you lost the wallet? M: I don't have any idea I had an appointment with Dr. Baker at nine o'clock. W: What time did you leave his office? M: At about 9: 30 or 9: 35. Then I went to the department store. After that I got into a taxi. W: Isn't it possible that it could have slipped out of your pocket in the taxi? M: I just don't know. Anyway, I could never find that same taxi again. What are they talking about?