Question

A rainforest is an area covered by tall trees with the total high rainfall spreading quite equally through the year and the temperature rarely dipping below 16℃.Rainforests have a great effect on the world environment because they can take in heat from the sun and adjust the climate.Without the forest cover，these areas would reflect more heat into the atmosphere，warming the rest of the world.Losing the rainforests may also influence wind and rainfall patterns，potentially causing certain natural disasters all over the world.

In the past hundred years，humans have begun destroying rainforests in search of three major resources(资源)：land for crops，wood for paper and other products，land for raising farm animals.This action affects the environment as a whole.For example，a lot of carbon dioxide(二氧化碳)in the air comes from burning the rainforests.People obviously have a need for the resources we gain from cutting trees but we will suffer much more than we will benefit.

There are two main reasons for this.Firstly，when people cut down trees，generally they can only use the land for a year or two.Secondly，cutting large sections of rainforests may provide a good supply of wood right now，but in the long run it actually reduces the world's wood supply.

Rainforests are often called the world's drug store.More than 25% of the medicines we use today come from plants in rainforests.However，fewer than 1%of rainforest plants have been examined for their medical value.It is extremely likely that our best chance to cure diseases lies somewhere in the world's shrinking rainforests.

1.Rainforests can help to adjust the climate because they ______.

A．reflect more heat into the atmosphere

B．reduce the effect of heat from the sun on the earth

C．bring about high rainfall throughout the world

D．rarely cause the temperature to drop lower than 16℃

2.What does the word“this”underlined in the third paragraph refer to?

A．Humans have begun destroying rainforests.

B．People have a strong desire for resources.

C．We will lose much more than we can gain.

D．Much carbon dioxide comes from burning rainforests.

3.It can be inferred from the text that ______.

A．we can get enough resources without rainforests

B．we will grow fewer kinds of crops in the gained land

C．the level of annual rainfall affects wind patterns

D．there is great medicine potential in rainforests

4.What might be the best title for the text?

A．Rainforests and the Environment

B．How to Save Rainforests

C．How to Protect Nature

D．Rainforests and Medical Development

Answer 1

1.B

2.C

3.D

4.A

【解析】

试题分析：本文主要介绍了热带雨林对于环境和人类的相互影响，他对于环境有保护和调节作用，以及热带雨林中的对于人类有益的药物原材料，但是人们对于热带雨林的破坏又对环境造成了很多不好的影响。

1. 们可以在第一段对于雨林的总括里去找到答案。根据Rainforests have a great effect on the world environment because they can take in heat from the sun and adjust the climate.可知：热带雨林对环境有巨大的影响，因为他们可以吸收阳光并且调节气候。故选B。

2. obviously have a need for the resources we gain from cutting trees but we will suffer much more than we will benefit.可知人们从砍伐树木中轻而易举的获得对于资源的需要，但是比起我们所获得的我们所遭受的损失却更多。故选C。

3. Places自然段中Rainforests are often called the world's drug store.More than 25% of the medicines we use today come from plants in rainforests.可以得知：热带雨林也被称作世界医药宝库，因为今天我们所使用的超过25%的药材都来自于热带雨林中的植物。故选D。

4. have a great effect on the world environment，可知热带雨林对于环境有巨大的影响，在文中二三四自然段分别叙述了热带雨林对于人类的影响及对于药材的贡献。故选A。

考点：考查说明文阅读。