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
When was the last time you saw a frog? Chances are, if you live in a city, you have not seen one for some time. Even in wet area
When was the last time you saw a frog? Chances are, if you live in a city, you have not seen one for some time. Even in wet area
admin
2011-01-05
45
问题
When was the last time you saw a frog? Chances are, if you live in a city, you have not seen one for some time. Even in wet areas once teeming with frogs and toads, it is becoming less and less easy to find those slimy, hopping and sometimes poisonous members of the animal kingdom. All over the world, even in remote jungles on the far side of the globe, frogs are losing the ecological battle for survival, and biologists are at a loss to explain their demise. Are amphibians
simply over-sensitive to changes in the ecosystem? Could their rapid decline in numbers be signalling some coming environmental disaster for us all?
This frightening scenario is in part the consequence of a dramatic increase over the last quarter of a century in the development of once natural areas of wet marshland; home not only to frogs but to all manner of wildlife. Yet, there are no obvious reasons why certain frog species are disappearing from rainforests in the Southern Hemisphere which are barely touched by human hands. The mystery is unsettling to say the least, for it is known that amphibian species are extremely sensitive to environmental variations in temperature and moisture levels. The danger is that planet Earth might not only lose a vital link in the ecological food chain (frogs keep populations of otherwise pestilent insects at manageable levels) , but we might be increasing our output of air pollutants to levels that may have already become irreversible. Frogs could be inadvertently warning us of a catastrophe.
An example of a bizarre occurrence regarding a species of frog dates from the summer of 1995 , when "an explosion” of multi-coloured frogs of the species Rana klepton esculenta occurred in the Netherlands. Normally these frogs are brown and greenish-brown, but some unknown contributory factor is turning these frogs yellow and / or orange. Nonetheless, so far, the unusual bi- and even tri-coloured frogs are functioning similarly to their normal-skinned contemporaries. It is thought that frogs with lighter coloured skins might be more likely to survive in an increasingly warm climate due to global warming.
One theory put forward to explain extinct amphibian species that seems to fit the facts concerns the depletion of the ozone layer, a well-documented phenomenon which has led to a sharp increase in ultraviolet radiation levels. The ozone layer is meant to shield the Earth from UV rays, but increased radiation may be having a greater effect upon frog populations than previously believed. Another theory is that worldwide temperature increases are upsetting the breeding cycles of frogs.
Some unknown contributory factor is turning frogs yellow and / or orange in the______.
选项
答案
Netherlands
解析
(答案见第三段。Netherlands荷兰。)
转载请注明原文地址:https://kaotiyun.com/show/iJVK777K
本试题收录于:
C类竞赛(非英语专业本科)题库大学生英语竞赛(NECCS)分类
0
C类竞赛(非英语专业本科)
大学生英语竞赛(NECCS)
相关试题推荐
(1)SANFRANCISCO—Aftermonthsoffeverishspeculation,StevenP.JobsintroducedWednesdaywhatApplehopeswillbethecoole
(1)ThestoryofthewestwardmovementofpopulationintheUnitedStatesis,inthemain,thestoryoftheexpansionofAmerica
(1)Whatcausesasorethroat?Manythingscancauseasorethroat.Thesecausesincludeinfectionswithvirusesorbacteria
Thisisapicture.Inthe【T1】________,thereisahousebuiltintothesideofabarehill.Thehouseisactuallycutoutofthe
Therehavebeenanumberofstudiesonsmokingamongtheyoung.【T1】________,ithasbeenfoundthatmanyofthechildrenliving
HowtoWriteResumesPreparations.consideryour【T1】________.decidewhichjobtitlesneedtheskillsandknowledg
This________bowlwasboughtfromChinaataratherhighprice,butitseemednoonecouldappreciateitsworth.
Wheredoesthisconversationprobablytakeplace?
Ifyou【D1】______smoothskinthatglowswithyouth,thechancesarethatatsomepointyouwillhaveheardtheexhortationtodri
Ifyou【D1】______smoothskinthatglowswithyouth,thechancesarethatatsomepointyouwillhaveheardtheexhortationtodri
随机试题
在《盛京刑部原档》中记载,清政权关外已经有了犯罪的初步分类,其规定应当判处死刑并不能援用赦免的罪是()。
EAI集成的深度上不包括
用避污纸垫着拿取物品或操作,保持________或用物________,以省略________。
病因于寒,素体阳虚,痰从寒化,属寒痰为患,则发为反复发作,正气耗伤或素体肺肾不足者,可表现为
依据《烟花爆竹安全管理条例》的规定,受理道路运输烟花爆竹申请的公安部门应当自受理之日起()日内对托运人提交的有关材料进行审查,对符合条件的,核发“烟花爆竹道路运输许可证”。
某施工单位在混凝土搅拌场处私设排污口,将生产过程中产生的废水直接排入水沟,经水沟进人稻田,形成了板结,使村里几十亩水稻受损严重。市环保局责令该施工单位限期改正,限期拆除私自设置的排污口,并对该施工单位处以()的罚款。
为了防范证券结算风险,我国设立了证券结算风险基金。下列各项所造成的登记结算机构的损失中可以用证券结算风险基金垫付或弥补,包括()。Ⅰ.违约交收Ⅱ.技术故障Ⅲ.操作失误Ⅳ.不可抗力
私募基金的合格投资者投资于单只私募基金的金额不低于()万元。
在软件需求工程中,需求管理贯穿整个过程。需求管理最基本的任务是明确需求,并使项目团队和用户达成共识,即建立______。
D分析句子结构可知,本句的主干是“Theimpressiveaspect...isitspervasivenessinhumanculture.”,句中的that______withit是that引导的定语从句,that指代these
最新回复
(
0
)