A、They lived in sturdy shelters. B、They used sand as insulation. C、They kept fires burning constantly. D、They faced their homes

M: Hey, Jane. What’s so interesting?
W: 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 the bunch 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 ways?
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, a primitive sort of solar heating.
M: Hey, that’s pretty smart!
W: Then people in the late Ice Age even insulated their homes by putting heated cobblestones on the floor.
M: I guess I spoke too soon.[15]Can I read that magazine article after you’re done? I think I’m going to try to impress my anthropology teacher with my amazing knowledge of Ice Age civilization.
W: Ha... What a show-off!
13. What did the man think about the people of the Ice Age?
14. How did people in the early Ice Age keep warm?
15. What does the man want the woman to do?