【正确答案】 B

【答案解析】[听力原文] 11-13
M: Talking about the 21st Century, as far as transportation is concerned, I think there're going to be huge changes in the way people use cars.They'll probably have made laws about what kind of car you can own and when you can use it.
W: And I bet it'll be impossible for people to use cars whenever they like. There'll be just too many of them on the roads.The air will be so seriously polluted that nobody will be able to breathe normally.
M: Exactly. People will have to rely on other modes of transportation — especially trains.
W: Why do you say that?
M: Well, we won't be able to use caps, and airports take too much space.With the supply of land for airports shrinking around the world, there are going to be fewer airports and fewer plane flights.That leaves trains.
W: Huh. So do you thinkthere will be more efficient train systems between cities?
M: Sure.Trains are relatively safer and cleaner, and they can enable people to take inter-city travel in a matter of hours.There may even be trains going under the oceans to connect the major continents.
W: Under the oceans? Get out of here! I get nervous enough flying on a plane.

【正确答案】 A

【正确答案】 A