听力原文:W: What are you doing, Bill? Writing a letter? M: Yes, and it's not easy. W: My Aunt Mabel sent me a gift for my birthday. I can't remember which gift was hers, but I want to thank her for it. M: Oh, that's a difficult problem. When it happens to me, I just write to say' Thank you for the wonderful girl' without saying what a gift was. Are you with me? W: Yes, thanks. That's a clever idea. M: When you have a bad memory, you have to be clever. (17)