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
At the base of a mountain in Tanzania’s Gregory Rift, Lake Natron burns bright red, surrounded by the remains of animals that we
At the base of a mountain in Tanzania’s Gregory Rift, Lake Natron burns bright red, surrounded by the remains of animals that we
admin
2021-01-08
75
问题
At the base of a mountain in Tanzania’s Gregory Rift, Lake Natron burns bright red, surrounded by the remains of animals that were unfortunate enough to fall into the salty water. Bats, swallows and more are chemically preserved in the pose in which they perished, sealed in the deposits of sodium carbonate in the water. The lake’s landscape is bizarre and deadly—and made even more so by the fact that it’s the place where nearly 75 percent of the world’s flamingos(火烈鸟)are born.
The water is so corrosive that it can burn the skin and eyes of unadapted animals. Flamingos, however, are the only species that actually makes life in the midst of all that death. Once every three or four years, when conditions are right, the lake is covered with the pink birds as they stop flight to breed. Three-quarters of the world’s flamingos fly over from other salt lakes in the Rift Valley and nest on salt-crystal islands that appear when the water is at a specific level—too high and the birds can’t build their nests, too low and predators can move briskly across the lake bed and attack. When the water hits the right level, the baby birds are kept safe from predators by a corrosive ditch.
"Flamingos have evolved very leathery skin on their legs so they can tolerate the salt water," says David Harper, a professor at the University of Leicester. "Humans cannot, and would die if their legs were exposed for any length of time. " So far this year, water levels have been too high for the flamingos to nest.
Some fish, too, have had limited success vacationing at the lake as less salty lagoons(泻湖)form on the outer edges from hot springs flowing into Lake Natron. Three species of tilapia(罗非鱼)thrive there part-time. " Fish have a refuge in the streams and can expand into the lagoons when the lake is low and the lagoons are separate," Harper said. "All the lagoons join when the lake is high and fish must retreat to their stream refuges or die. " Otherwise, no fish are able to survive in the naturally toxic lake.
This unique ecosystem may soon be under pressure. The Tanzanian government has once again started mining the lake for soda ash, used for making chemicals, glass and detergents. Although the planned operation will be located more than 40 miles away,drawing the soda ash in through pipelines, conservationists worry it could still upset the natural water cycle and breeding grounds. For now, though, life prevails—even in a lake that kills almost everything it touches.
Flamingos in the Rift Valley are unique in that______.
选项
A、they can move swiftly across lagoons
B、they can survive well in salty water
C、they breed naturally in corrosive ditches
D、they know where and when to nest
答案
B
解析
推理判断题。第二段提到,火烈鸟是唯一生活在纳特龙湖的物种。紧接着定位句提到火烈鸟的腿上已经进化出非常坚韧粗糙的皮肤,这样它们就可以耐受盐水。由此可知,东非大裂谷的火烈鸟独特的原因是它们粗糙的腿部皮肤让它们可以在盐水中生存并繁殖,故答案为B)。
转载请注明原文地址:https://kaotiyun.com/show/caP7777K
0
大学英语六级
相关试题推荐
A、Launchingacampaigninspecialistmedicaljournals.B、AdvertisingmedicinesthatneedaprescriptiononTV.C、Makingnewspape
A、Lookinthemirroranddotheself-talk.B、Getwellpreparedbeforemakinganychange.C、Makealittlechangesintheirlifest
Naturally,inagroupofanimalsasdiverseasthesnakes,andwithsomanyvariedenemies,therearenumerousdefensivereactio
Carmakershavelongusedsextoselltheirproducts.Recently,however,bothBMWandRenaulthavebasedtheirlatestEuropeanm
TheHistoryofChineseAmericans[A]ChinesehavebeenintheUnitedStatesforalmosttwohundredyears.Infact,theChines
TheHistoryofChineseAmericans[A]ChinesehavebeenintheUnitedStatesforalmosttwohundredyears.Infact,theChines
It’sagoodideatoapplysunscreenbeforeheadingtothebeachifyoudon’twanttoburn.Butformarineanimalslikewhales,t
It’sagoodideatoapplysunscreenbeforeheadingtothebeachifyoudon’twanttoburn.Butformarineanimalslikewhales,t
Peopletravelinglongdistancesfrequentlyhavetodecidewhethertheywouldprefertogobyland,sea,orair.Hardlycananyon
随机试题
下列说法正确的是()。
由于冬季气候寒冷,英国人爱吃辣味的食物。()
以下哪些可以作为诊断肺心病的主要依据
根据我国《公司法》的规定,下列()属于公司章程绝对必要记载事项。
施工试验报告及见证检测报告汇总的工程文件档案资料是()。
依据《水污染防治法实施细则》,不跨省、自治区、直辖市的生活饮用水地表水源保护区的划定,由( )协商提出划定方案,报省级人民政府批准。
道格拉斯.麦克格雷格的经典的X理论,指的是()。
甲公司2014年度至2016年度对乙公司债券投资业务的相关资料如下:(1)2014年1月1日,甲公司以银行存款900万元购入乙公司当日发行的5年期公司债券,作为持有至到期投资核算,该债券面值总额为1000万元,票面年利率为5%,每年年末支付利息,到期一次
软件危机出现于60年代末,为了解决软件危机,人们提出了______的原理来设计软件,这就是软件工程诞生的基础。
ApossiblematchforfemaleDis______.
最新回复
(
0
)