听力原文：W: Are you sure that we'll be safe? M: Take it easy. All the ski runs are carefully marked. And anything that might be dangerous, like a cliff or something, is enclosed by a fence. W: I'm still nervous. I'm going to break my leg. M: Don't worry. I'll ski with you for a half-hour or so. We'll go on the bunny hill. W: What is the 'bunny hill'? M: It is the easiest run on the mountain. Most first-time skiers start to learn skiing on the bunny hill for it isn't steep at all. W: So there are runs for different kinds of skiers? Are there runs for advanced skiers and runs for beginners? M: Absolutely. Look at this map. You can see all the runs on the mountain on this map. The advanced runs are marked with red circles and the beginner runs have white diamonds. W: Then what about the green squares? M: They are the intermediate runs. W: So why don't I get a map like that? M: I'll get you one later. So now let's ski! (23)