4.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 l6℃.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 l%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.
72.Rainforests can help to adjust the climate because theyD.
A.reflect more heat into the atmosphere
B.bring about high rainfall throughout the world
C.rarely cause the temperature to drop lower than l6℃
D.reduce the effect of heat from the sun on the earth
73.What does the word"this"underlined in the third paragraph refer to?A
A.We will lose much more than we can gain. B.Humans have begun destroying rainforests.
C.People have a strong desire for resources. D.Much carbon dioxide comes from burning rainforests.
74.It can be inferred from the text thatB.
A.we can get enough resources without rainforests
B.there is great medicine potential in rainforests
C.we will grow fewer kinds of crops in the gained land
D.the level of annual rainfall affects wind patterns
75.What might be the best title for the text?C
A.How to Save Rainforests
B.How to Protect Nature
C.Rainforests and the Environment
D.Rainforests and Medical Development.
分析 本文叙述了热带雨林在人们生活中的重要作用,它们能吸收太阳光调节地球上的温度,如果没有它们人类会得疾病,给人类带来大的灾难,并且它们还能提供一些药用的植物药材,来为人类治病,因此,我们要保护热带雨林,不要滥垦滥伐.
解答 72.D 73.A 74.B 75.C
72.D.细节理解题.根据Rainforests have agreat effect on the world environment because they can take in heat from thesun and adjust the climate.热带雨林有一个很大的影响对于世界环境,因为他们能吸收来自太阳的热量,调节气候.故选D.
73.A.词义猜测题.根据People obviously have a need for the resources we gain from cutting trees but we will suffermuch more than we will benefit可知人们失去的会比得到的多.故选A.
74.B.推理判断题.根据More than 25% of the medicines we use today come from plants inrainforests.However,fewer than l%ofrainforest plants have been examined for their medical value.It is extremelylikely that our best chance to cure diseases lies somewhere in the world'sshrinking rainforests.热带雨林里有很多的药用植物供我们开采利用,故选B.
75.C.主旨大意题.本文是在向读者介绍热带雨林的减少会对环境造成的影响,呼吁人们要保护热带雨林,进而保护整个人类生存的环境;故选C.
点评 阅读理解题测试考生在阅读基础上的逻辑推理能力,要求考生根据文章所述事件的逻辑关系,对未说明的趋势或结局作出合理的推断;或根据作者所阐述的观点理论,对文章未涉及的现象、事例给以解释.考生首先要仔细阅读短文,完整了解信息,准确把握作者观点.