Rainforests are home to a rich variety of medicinal plants, food, birds and animals. Can you believe that a single bush（灌木丛）in the Amazon may have more species of ants than the whole of Britain! About 480 varieties of trees may be found in just one hectare of rainforest.
雨林是丰富多样的药用植物、食物、鸟类和动物的家园。你能相信吗，在亚马逊的一个灌木丛中可能有比整个英国还要多的蚂蚁品种！仅仅一公顷的雨林就可能有大约480种树木。

Rainforests are the lungs of the planet-storing vast quantities of carbon dioxide and producing a significant amount of the world’s oxygen. Rainforests have their own perfect system for ensuring their own survival; the tall trees make a canopy（树冠层）of branches and leaves which protect themselves, smaller plants, and the forest animals from heavy rain, intense dry heat from the sun and strong winds.
雨林是地球的肺——储存大量的二氧化碳并产生世界上相当一部分的氧气。雨林拥有自己完美的生存系统；高大的树木形成了一个由树枝和叶子组成的树冠层，这层树冠层保护了它们自己、较小的植物和森林动物免受大雨、强烈的阳光干燥和强风的侵袭。

Amazingly, the trees grow in such a way that their leaves and branches, although close together, never actually touch those of another tree. Scientists think this is the plants’ way to prevent the spread of any tree diseases and make life more difficult for leaf-eating insects like caterpillars. To survive in the forest, animals must climb, jump or fly across the gaps. The ground floor of the forest is not all tangled leaves and bushes, like in films, but is actually fairly clear. It is where dead leaves turn into food for the trees and other forest life.
令人惊奇的是，树木生长的方式使得它们的叶子和枝条虽然彼此靠近，但实际上从不触碰到另一棵树的叶子和枝条。科学家认为这是植物防止树木疾病传播的方式，同时也让像毛毛虫这样的食叶昆虫生活更加困难。为了在森林中生存，动物必须攀爬、跳跃或飞越这些间隙。森林的地面并不像电影中那样全是纠缠的叶子和灌木，实际上相当清晰。这里是死去的叶子转化为树木和其他森林生物食物的地方。

They are not called rainforests for nothing! Rainforests can generate 75%of their own rain. At least 80 inches of rain a year is normal-and in some areas there may be as much as 430 inches of rain annually. This is real rain-your umbrella may protect you in a shower, but it won’t keep you dry if there is a full rainstorm. In just two hours, streams can rise ten to twenty feet. The humidity（湿气）of large rainforests contributes to the formation of rainclouds that may travel to other countries in need of rain.
它们被称为雨林是有原因的！雨林可以产生75%的自己的雨水。每年至少80英寸的降雨是正常的——在一些地区，年降雨量可能高达430英寸。这是真正的雨——你的雨伞可能在阵雨中保护你，但如果是一场大雨，它也无法让你保持干燥。在仅仅两小时内，溪流可能会上升十到二十英尺。大型雨林的湿度有助于形成雨云，这些雨云可能会飘移到需要雨水的其他国家。

1. What can we learn about rainforests from the first paragraph? （ ）
   A. They produce oxygen. B. They cover a vast area.
   C. They are well managed. D. They are rich in wildlife.
   答案：D

2. Which of the following contributes most to the survival of rainforests? （ ）
   A. Heavy rains B. Big trees.
   C. Small plants. D. Forest animals.
   答案：B

3. Why do the leaves and branches of different trees avoid touching each other? （ ）
   A. For more sunlight. B. For more growing space.
   C. For self-protection. D. For the detection of insects.
   答案：C

4. What can be a suitable title for the text? （ ）
   A. Life-Giving Rainforests B. The Law of the Jungle
   C. Animals in the Amazon D. Weather in Rainforests
   答案：A