首页
登录
职称英语
This passage is adapted from material published in 1993
This passage is adapted from material published in 1993
游客
2025-02-19
33
管理
问题
This passage is adapted from material published in 1993
The recent recognition of a link between increasing rates of deforestation and increasing global climatic warming has focused new attention on the ecological role of forests. Deforestation threatens the continued existence o forests, and their loss would lead to an immediate, irreversible destabilization of the climate because the destructio of forests contributes to increased atmospheric concentrations of such heat-trapping gases as carbon dioxide and therefore to the acceleration of global warming.
The world is at present accumulating carbon dioxide in the atmosphere from two well-known sources: the combustion of fossil fuels and deforestation. Deforestation results in higher levels of carbon dioxide in the atmosphere because the carbon stored in plants and trees is released when trees decay or are burned. A third sources, the warming-enhanced decay of organic matter in forests and soils, especially in the middle and higher latitudes, is now being recognized as potentially significant. Evidence is accumulating that carbon from this source is beginning to have global effects. Thus, two of the three sources of carbon dioxide in the atmosphere are directly related to the survival and health of forests.
In the discussion about the importance of forests, however, emphasize has fallen on biodiversity, or numbers of species per unit area, especially in the tropics, where such diversity is particularly high. But forests, it should be emphasized, have a similar role in every latitude. They contain the largest numbers of different kinds of plants and animals of any community on land and might be considered the most highly developed of the terrestrial communities from the standpoint of complexity of structure and diversity of life and life forms. Forests are far more than simple collections of species, however. It is unfortunate that the discussion of biotic or living resources has been focused on biodiversity rather than on the actual ability of the land itself to support life. In order for the complete range of plant and animal life to thrive, the soil must contain essential nutrients in their proper quantities and proportions, and the atmosphere must be composed of the correct molecules in their proper proportions. If the soils were to become infertile and the atmosphere inhospitable, more than mere diversity or numbers of species would be lost, the land would become impoverished and no longer be able to support any life. [br] The passage is primarily concerned with discussing the
选项
A、importance of forests for protection the land and atmosphere
B、role of forests in the tropics versus that in the higher latitudes.
C、process of deforestation in the tropics
D、need for forests to ensure the preservation of biodiversity
E、negative effects of recent global climatic changes in forests.
答案
A
解析
转载请注明原文地址:http://tihaiku.com/zcyy/3963998.html
相关试题推荐
Thispassageisadaptedfrommaterialpublishedin1993
Thispassageisadaptedfrommaterialpublishedin1993
Asitwaspublishedin1935,MulesandMen,ZoraNealeHurston’slandmarkco
Asitwaspublishedin1935,MulesandMen,ZoraNealeHurston’slandmarkco
Asitwaspublishedin1935,MulesandMen,ZoraNealeHurston’slandmarkco
Thispassageisadaptedfrommaterialpublishedin2002.In1971,hoton
Thispassageisadaptedfrommaterialpublishedin2002.In1971,hoton
BiologistsstudyingwildmonkeyssometimesneedthegeneticmaterialDNAfro
READINGPASSAGE2Youshouldspendabout20minutesonQuestions14-26,whichar
READINGPASSAGE2Youshouldspendabout20minutesonQuestions14-26,whichar
随机试题
Whomostlikelywillattendthefair?[originaltext]Thisyear’scollegegraduate
Weshouldbe(consider)______ofthecomfortofoldpeople.consideratebe是系动词,后面要
成人上腹部CT检查前30分钟口服阳性对比剂的量是A.50~80ml B.100
下述哪项不是Crohn病常见的临床表现A.发热 B.脓血便 C.腹痛 D.
呼吸的反射性调节中,可将呼吸道内的异物或分泌物排出的有()。A.咳嗽反射 B
下列各项中,不属于槟榔主治病证的是A、疟疾 B、水肿 C、胆结石 D、食积
斑蝥米炒时,每100kg药物用米A.25kg B.5kg C.10kg
各种运输方式内外部的各个方面的构成和联系,就是( )。 A.运输系统
根据我国安全生产法,生产经营单位的主要负责人应承担的安全生产职责有( )。A.
依照《立法法》的规定,下列事项只能制定法律的是()。A.国家主权的事项 B.犯
最新回复
(
0
)