听力原文：M: Hi. I have some good news for you. W: What is it? M: The teacher suggested that we go on a trip this Saturday. W: Oh, wonderful. Where shall we go? M: How about going to the park? W: I don't think it's a good place to go to. We can go there another time. We should go farther away this time. M: Where do you think we should go then? W: How about the reservoir in the suburbs? M: I don't think it's a good idea. It's not safe. Why not go to the mountain instead? W: That sounds good. Let's go to the mountains to the south of the city. (18)