考前必看：2021年考研英语工学类阅读理解模拟题及答案（十三）

发布时间：2020-10-12

英语是考研初试当中比较拉分的科目，历来令不少考生又爱又恨。许多考生的英语都有很大的进步空间，因此英语该如何学就成为了众多考生关心的重点。想要学好英语，实战经验很重要。下面，51题库考试学习网为大家带来考研初试英语科目的一些模拟试题，正在备考的小伙伴赶紧练起来吧。

Tropical rainforests cover over an area of nearly 3 billion acres，or about 8.3 percent of the Earth‘s total 1and surface.These remarkable forests are shared by some 50 countries on five continents.Biologists believe that rainforests are the home of perhaps half the world’s biotic species，about five-sixths of which have not yet been described and named.

Throughout most of history，rainforests were considered to be remote，inaccessible，and unpleasant places，and as a result they were 1ittle affected by human activities.In the present century，however，rainforests have been exploited and ruined at a quickening pace，and in the last decade or so，tropical deforestation has become one of the Earth‘s most serious environmental problems.The rate of deforestation is spectacular—51 acres per minute;74，000 acres per day;27 million acres per year.More than half of the original African rainforest is now gone;about 45 percent of Asia’s rainforest no longer exists;the proportion in Latin America is approaching 40 percent.

As the forest goes，so goes its animal life.In the mid-1980s it was calculated that tropical deforestation was responsible for the extinction of one species per day;by 1990 it was estimated that the rate was one species per hour.

Moreover，loss of the forests contributes to increased soil erosion，drought，flooding，worsening water quality，declining agricultural productivity，and greater poverty for rural inhabitants.In addition，atmospheric carbon dioxide continues to be increased because there are fewer trees to absorb it and because burning of trees for forest clearing releases more to the air.

The irony of tropical deforestation is that the anticipated economic benefits are usually illusory.Much of the forest clearing，especially in Latin America，is in response to the social pressure of overcrowding and poverty in societies where most of the people are landless.The governments open up“new lands”for settlement in the rainforest.The settlers clear the land for crop growing or livestock raising.The result almost always is an initial one or two years of high soil productivity，followed by poor years as fertility declines and the soil begins to suffer from erosion.

The forests，of course，are renewable.If left alone by humans，they can regenerate，as long as there are seed trees in the neighborhood and the soil has not lost all its nutrients.The loss of biotic diversity，however，is much more serious.Extinction is an irrecoverable process.Valuable potential resources may disappear before they are even discovered.Natural genotypes that could be combined with agricultural crops or animals to resist disease，insects，parasites，and other environmental stresses may also be lost.Last，but not least，is the possibility that many small，isolated valuable groups of native people may be wiped out.

Much concern has been expressed about tropical deforestation，and some concrete steps have been taken.The development of agroforestry (planting crops with trees，rather than cutting down the trees and replacing them with crops) is being fostered in many areas.In Brazil，which has by far the largest expanse of rainforest，some 46，000 square miles of reserves have been set aside，and Brazilian law requires that any development in the Amazon region leave half of the land in its natural state.In 1985 a comprehensive world plan，sponsored by the World Bank，the World Resources Institute，and the United Nations Development Programme，was introduced.It proposes concrete，country-by-country strategies to combat tropical deforestation.It is an $ 8 billion，five-year project，dealing with everything concerning the protection of rainforests.

Meanwhile，the sounds of the axe and the chain-saw and the bulldozer continue to be heard throughout the tropical forest lands.

1. In the past，rainforests were nearly left intact because____.

[A]people then had a better sense of environmental protection

[B]people then knew better how to protect them

[C]people then looked at rainforests in some awe

[D]people then did not know how to exploit them

2. Which of the following is NOT mentioned as a result of deforestation?

[A]Loss of species diversity.

[B]Increased poverty for the concerned countries.

[C]Increased atmospheric pollution.

[D]Loss of culture diversity.

3. It can be inferred from the passage that forest destruction mainly results from____.

[A]people‘s desire to meet their economic needs

[B]people‘s ignorance of the importance of forests to biotic species

[C]people‘s need to burn fuel to warm their houses

[D]people‘s desire to open up more farmland

4. People‘s attempt to clear the forest to open up new lands often has the result of____.

[A]leaving even more people homeless

[B]expanding settlement but destroying the land

[C]finding more land for landless people to cultivate

[D]renewing the forest at a slower pace

5. The tone of the author‘s conclusion seems to be ____.

[A]optimistic [B]objective

[C]concerned [D]tolerant

参考答案：

1. [C] 意为：人们当时用敬畏的眼光看待热带雨林。参阅第二段第一句。

2. [B] 意为：使相关国家更贫困。第四段第一句只提到了给农村居民(rural inhabitants)带来的贫困状况。有关[A]参阅第三段和第六段，有关[C]参阅第四段第二句，有关[D]参阅第六段最后一句。

3. [A] 参阅第五段第一、二、三、四句。相比较而言，[D]表达的意思则有些片面。

4. [B] 意为：扩展了定居点，但毁坏了土地。参阅第五段。

5. [C] 意为：关注。参阅最后一段。

以上就是51题库考试学习网为大家带来的全部内容，希望能给大家一些帮助。51题库考试学习网提醒：在最后阶段，调整自己的心态也是非常重要的，每年都有考生临考前放弃，所以小伙伴们要注意不要给自己太大的压力哦。另外，小伙伴们如果还有其他关于考研信息的疑问，也可以留言咨询哦。

下面小编为大家准备了研究生入学的相关考题，供大家学习参考。

心电图示：P波形态、时限正常，下传的P-R间期正常。部分P波后无QRS波，出现一长间隙，长间隙时间与窦性P-P间距成整倍数关系，应诊断为
A.房室分离 B.房室传导阻滞
C.窦房传导阻滞 D.室性逸搏心律

答案：C

解析：

①正常人心脏冲动由窦房结发出,先激动心房,再向下激动心室。房室分离的病人,出现两个冲动产生点,心房的冲动点控制心房,心室的冲动点控制心室。因此心房去极化产生的P 波与心室去极化产生的QRS波无关。房室分离包括三度房室传导阻滞和干扰性房室脱节，前者心室率较慢,常 60次/分,P波个数多于QRS波；后者心室率较快,常 60次/分，P波个数少于QRS波；由此可见，第139题为干扰性房室脱节引起的房室分离。②窦房传导阻滞时,窦房结产生的冲动不能使心房除极或使心房除极延迟,表现为PP间期显著延长,其长度为窦性PP间期的2倍或整数倍。因此第140 题答案为C。房室传导阻滞分为一、二、三度,一度阻滞P波和QRS波顺序发生,无QRS波脱落；二度I 型和II型阻滞均可有QRS波的脱落,但二度I型阻滞表现为PR间期进行性延长,二度II型阻滞表现为 PR间期正常,三度阻滞表现为P波和QRS波各自独立,互不相关,均与试题给定的条件不符。

下列哪种情况的糖尿病不需要使用胰岛素治疗？
A.合并严重感染 B.糖尿病酮症酸中毒 C.肥胖患者 D.围手术期

答案：C

解析：

胰岛素治疗的适应证：①1型糖尿病；②糖尿病酮症酸中毒、高血糖高渗状态和乳酸性酸中毒伴髙血糖；③各种严重的糖尿病急性或慢性并发症；④手术、妊娠、分娩；⑤2型糖尿病β细胞功能明显减退者；⑥某些特殊类型糖尿病。肥胖患者不是胰岛素的适应证(C)。