英语听力教程第三版(张民伦主编)Unit 1 The Earth at Risk听力原文
{ More domestic animals —> more plants —> fewer available plants} —>
more desert —> move south —>desert expanding south —> no grass
2. Why is the rain so important to soil? Growing crops stabilize soil, without them the top soil just blows away. But if there isn't enough rain the crops don't grow. 3. What are some of the reasons that tropical forests are being cut down? People try to grow food to support themselves or to create ranches where cattle can be raised, or to get hardwood for export, or to make way for mines.
Audioscript:
I — Interviewer B — Brian Cowles
I:Brian Cowles is the producer of a new series of ｄｏｃｕｍｅｎ
ｔaries called "The Earth at Risk" which can be seen on Channel 4 later this month. Each program deals with a different continent, doesn't it, Brian?