首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
All along me chain of biological evolution, the extinction of species appears to have been a stage in the process of adapting ge
All along me chain of biological evolution, the extinction of species appears to have been a stage in the process of adapting ge
admin
2010-02-20
35
问题
All along me chain of biological evolution, the extinction of species appears to have been a stage in the process of adapting genetic lineages to changing environmental conditions. Although some catestrophic extinction occurred naturally, producing total loss of a genetic line, such catastrophes were comparatively rate. In modern times, however, human activities have altered the fundamental nature of this process, resulting in nearly total genetic losses.
It is not difficult to gain general agreement that man -induced increases in the endangerment and extinction of wildlife whether due to habitat alteration or loss, pollution, insufficiently regulated hunting, or other factors are undesirable. It is, however, more difficult to obtain consensus when consideration is given to the economic costs of correcting such trends, including natural habitat preservation, regulation of pesticides and other toxic substances, and wildlife and park management. Endangered species often are, in effect, competitors with humans for habitat and other resources which also provide other kinds of human use and need.
Measures needed to protect endangered species vary considerably in difficulty and cost. Of the approximately 400 inverterate species which at present appear to be threatened, for example, about one third could probably be restored by such inexpensive means as modifying the boundaries of designated natural are as, acquiring and protecting caves and other small areas which contain the particular species, and additional management ’of parks and refuges.
Another one - third of the endangered lower animal species are threatened principally by water pollution and could be protected by improved control, particularly of five southern rivers.
The remaining one - third of the 400 endangered shellfish species would be considerably more difficult to protect. These are threatened by complex factors, such as overcollecting, channelization, highway and housing development, clams introduced species such as the Asian snail, dredging, quarry washing, poor erosion control, and lowering of water table.
The identification of threatened species and other significant wildlife trends must precede any corrective measures, and our knowledge base for making such identification is deficient in many respects. Our present lists of threatened species and subspecies are known to be incomplete, except in those geographical areas which contain habitats of species that have important commercial or sports harvest value.
Which of the followings is neither expressed nor implied in the passage as being a threat posed by man to wildlife preservation?
选项
A、The discharge of chemical wastes into streams as a result of industrial development.
B、Large -scale housing development.
C、Poor coordination of international efforts at park and refuge management.
D、Introduction of species into environments.
答案
C
解析
文章中并没讲到国际上是怎样合作来对濒临灭绝动物进行保护的,而其余几个选项要么直接可以从文中找到,要么在文中有暗示。
转载请注明原文地址:https://jikaoti.com/ti/619YFFFM
0
专业英语八级
相关试题推荐
Usingapublictelephonemaywellbeoneof【C1】______oflife,demandingpatience,determinationand【C2】______,togetheronoccas
Usingapublictelephonemaywellbeoneof【C1】______oflife,demandingpatience,determinationand【C2】______,togetheronoccas
Codeswitchingiswhenpeopleswitch,orchange,fromonelanguagetoanotherwhilespeaking.Theymightbeginaconversationin
A、IbitmytonguewhilespeakingSpanish.B、I’mgraduallyimprovingmySpanish.C、I’mnottakingenoughSpanishclassesduringa
ItwasadaythatMichaelEisnerwouldundoubtedlyliketoforget.SittinginaLosAngeleswitnessboxforfourhourslastweek
A、Writing.B、Intensivereading.C、Conversational.D、Listening.C
A、Ibarelyhadenoughtimetofinishmypaper.B、Ididn’thearthephonebecauseIwastyping.C、SomeonecalledjustasIstarte
"NewPrice";"JustReduced";"PricedtoSell".Onceunheardof,thesetagsarecroppingupevermoreofteninthepropertysecti
Oureducationsystemmustrespondinkindandstartteachingchildrenabouttherisksinvolvedinsexbeforetheyevenconsider
Longbeforerecordedhistory,ourancestorswerebathingforpleasureandhealth.Manhasfoundmanyinterestingwaystotakehi
随机试题
现场勘查笔录正文部分中勘查过程主要应写明哪些内容?
A.红肿病灶与正常组织无明显界限B.有波动感和压痛C.感染灶质地坚韧,表面有多个黄色脓点D.全身不同部位有多个毛囊和皮脂腺的炎症E.病灶呈片状红晕,边界清楚、压痛蜂窝组织炎
肝肾综合征的关键发病机制是
办理个人教育贷款时,贷后管理环节面临的操作风险不包括()。
银行业金融机构的各类贷款合同在各方当事人签章前应当进行规范性审查。规范性审查应确保()。
歌德,德国伟大的诗人和思想家,德国文学最高成就的代表,代表作《浮士德》被认为是18世纪末至19世纪初德国在艺术上的最高成就,他的《最后一课》曾人选初中语文课本。()
伞:雨衣()
(2013联考55)近几年中国的投资环境发生了根本性的变化,劳动力成本上升、劳动保护加强、土地成本上升、环保成本上升、能源资源使用成本上升、优惠政策取消,外资企业需要在更高的成本上与内资企业竞争,这是外资企业必须正视的事实和趋势。但要素和能源资源成本上升,
Whomcanyoutrustthesedays?ItisaquestionposedbyDavidHalpernofCambridgeUniversity,andtheresearchersattheDowni
Whatisrhythminliteratureaccordingtothepassage?
最新回复
(
0
)