听力原文:M: How long shall we stay at the Grand Canyon? W: A day? M: Well, I think we need a bit mom time. There's so much m see around there. How about two days? W: OK. That sounds reasonable. M: What about Yellowstone? The travel agent suggested four days there. W: I think that's tm much. We don't have enough time. Let's plan on three. M: OK. And a clay at Mount Rushmore? W: Right. I just want m see the stone faces. M: And how many extra days in Washington? Two? Three? W: Two. That'll give us five days there all together. M: Yes. OK. And that leaves two days for the redwood trees in Sequoia National Park. W: Maybe me day would be bettor. Then we'd have extra time in San Francisco. M: Oh, I don't know. I'd rather stay in Sequoia for an extra day. W: All right. That's ok with me. (20)