听力原文：M: Hey, Jane. What' s so interesting? W: What? Oh, hi, Tom. I' m reading this fascinating article on the societies of the Ice Age. M: The Ice Age? There weren't any societies then, just groups of cave people. W: That' s what people used to think. But a new exhibition at the American Museum of National History shows that Ice Age people were surprisingly advanced. M: Oh, really? In what way? W: Well, Ice Age people were the inventors of languages, art and music as we know it, And they didn' t live in caves. They built their own shelters. M: What did they use to build them? The cold weather would have killed almost all of the trees, so they couldn' t have used wood. W: In some warmer climates, they did build houses of wood. In other places, they used animal bones and skins or lived in natural stone shelters. M: How did they stay warm? Animal skin walls don't sound very sturdy. W: Well, it says here, that in the early Ice Age, they often faced their homes towards the south to take advantage of the sun. M: Hey, that' s pretty smart ! I guess I spoke too soon. Can I read that magazine article after you' re done? W: No problem. (20)