听力原文：Helen: What do you think of Potter's lecture? Jane: Not much. Helen: Why, what's wrong with it? Jane: Oh, I don' t know. It' s just that he.. well, because he overloads it with detail. He does tend to do this kind of thing I think. That course he gave on town planning last year. It was just the same--just a load of details, which you could have got from a book anyway, and more and more technical terms, there was no.. no overall ..er... Brian: No general overview you mean. Jane: Yes, I suppose you could call it that. I couldn't see the town for the buildings. Helen: But you've got to have detail in this kind of subject Jane, and anyway I think he is good. You take his first lecture for instance---I thought that was very interesting, and not at all over-detailed. Jane: But that' s just it Helen. That is just what I am getting at. He starts off all right and engages your interest so that you sit back and think' I am going to enjoy this. I am going to get a general idea of the important points in this topic.' Brian: Now, let' s keep this on an impartial academic level. At least we agree that he starts off on the right foot with his nice interesting introductions. Wouldn't you say that was important for any lecture? --to get the audience involved right at the beginning and then gradually increase the pressure. What is the possible relationship between the speakers?