英语听力教程第三版(张民伦主编)Unit 1 The Earth at Risk听力原文
rare plant：珍稀植物
rainfall：降雨
extinct：灭绝的;绝种的
carbon dioxide：二氧化碳
oxygen：氧
century：世纪
interview：采访 Do you know what happens to a rain forest when the trees are chopped down? About 80% of the rain forests nutrients come from trees and plants. That leaves 20% of the nutrients in the soil. The nutrients from the leaves that fall are instantly recycled back into the plants and trees. When a rain forest is clear-cut, conditions change very quickly. The soil dries up in the sun. When it rains, it washes the soil away. A Listen to the first part of an interview. Note down the key words in the notes column. Then answer the questions. Questions:
1. What is the vicious circle mentioned by Brian Cowles? More people ——>. more firewood ——> fewer trees