首页
登录
职称英语
Frog When was the last time you saw a frog? Cha
Frog When was the last time you saw a frog? Cha
游客
2023-07-28
1
管理
问题
Frog
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, and even in remote parts of Australia, frogs are losing the ecological battle for survival, and biologists are at a loss to explain their demise. Are amphibians simply oversensitive to changes in the ecosystem? Could it be that their rapid decline in numbers is signaling some coming environmental disaster for us all? This frightening scenario is in part the consequence of a dramatic increase over the last quarter century in the development of once natural areas of wet marshland-home not only to frogs but to all manner of wildlife. However, as yet, there are no obvious reasons why certain frog species are disappearing from rainforests in Australia that have barely been touched by human hand. 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 species of frog that, as far as is known, has become extinct, is the platypus frog. Like the well-known Australian mammal it was named after, it exhibited some very strange behavior, instead of giving birth to tadpoles in the water, it raised its young within its stomach. The baby frogs were actually born from out of their mother’s mouth. Discovered in 1981, less than ten years later the frog had completely vanished from the crystal clear waters of Booloumba Creek near Queensland’s Sunshine Coast. Unfortunately, this freak of nature is not the only frog species to have been lost in Australia. Since the 1970s, no less than eight others have suffered the same fate.
One theory 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. [br] Frogs’ rapid decline may be ______ some coming environmental disaster.
选项
答案
signaling
解析
第一段第六句。
转载请注明原文地址:https://www.tihaiku.com/zcyy/2875302.html
相关试题推荐
WhenmenreturnedfromWorldWarIIandthepostwar"babyboom"began,Americans
WhenmenreturnedfromWorldWarIIandthepostwar"babyboom"began,Americans
[audioFiles]audio_eufm_062(20101)[/audioFiles]A、Givingadvice.B、Discussion.C、
[audioFiles]audio_eufm_062(20101)[/audioFiles]A、Makesaspeech.B、Arrangestopi
[audioFiles]audio_eufm_061(20101)[/audioFiles]A、Steelcables.B、Anopencarriag
[audioFiles]audio_eufm_061(20101)[/audioFiles]A、Theyweredrivenbysteamengin
[originaltext]M:Isthatamap?Areyougoingsailingorsomething?W:Iwish.
[originaltext]M:Isthatamap?Areyougoingsailingorsomething?W:Iwish.
[originaltext]M:Isthatamap?Areyougoingsailingorsomething?W:Iwish.
[originaltext]M:I’dliketospeaktoMr.Jones,please.W:Sorry,sir.ButMr.
随机试题
一足月婴儿,顺产,无窒息,母乳喂养,生后2天,胆红素为268μmol/L,母亲血
用位移法求解图示结构,独立的基本未知量个数为( )。 A、1 B、2 C
迈克尔波特认为在一个行业中,存在看哪些基本的竞争力量。( ) I.潜在的加入
现代金融理论的三大支柱是()。A.风险管理 B.金融工程 C.时间价值
高浓度葡萄糖、尿素或造影剂皆不影响的比重测定方法为A.称量法B.折射仪法C.超声
“长期借款”账户主要用来核算归还期在()的各种借款的取得、归还情况。A.半年以内
绿藤资本发展区块链模式,在我国东北地区投资一片工业园,在园区新建一座招商大厦,该
在进行项目的现金流量估算时,影响每年净营业现金流量的因素有()。A.资本成本
甲企业将货物卖给乙企业,双方订立了买卖合同,丙企业作为该合同的担保人,丁先生作为
固定总价合同的适用范围有()。A.在工程过程中环境因素(特别是物价)变化小,工
最新回复
(
0
)