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
Spring is usually prime food time for some 1,200 polar bears along Canada’s Hudson Bay. Each year they plunder the bay’s ice flo
Spring is usually prime food time for some 1,200 polar bears along Canada’s Hudson Bay. Each year they plunder the bay’s ice flo
admin
2010-09-10
23
问题
Spring is usually prime food time for some 1,200 polar bears along Canada’s Hudson Bay. Each year they plunder the bay’s ice floes, smash open the snow caves of seals, and stuff themselves on seal pups. But in recent years the bears’ feast has turned into slimmer pickings. Why?
Temperatures at Hudson Bay have risen by one half degree Fahrenheit every decade since 1950. Winter ice on the bay melts three weeks earlier than it did just 25 years ago, which means three fewer weeks of polar bear mealtime. Result: Polar bears are 10 percent thinner and produce 10 percent fewer cubs than they did 20 years ago. And though climatologists hotly debate the causes behind Earth’s Arctic meltdown, "these changes are startling and unexpected,’ says James McCarthy, co-leader of the United Nations Intergovernmental Panel on Climate Change.
The plight of polar bears is just the tip to the iceberg when it comes to mounting evidence of global warming. "There’s definitely a stark contrast with the way things were at the start of the 20th century," says atmospheric scientist Leonard Druyan, of Columbia University. Recent data show the volume of Arctic sea ice has shrunk 20 percent since the 1950s; glaciers around the world are melting at rapidly increasing rates. Rivers and lakes in North America, Asia, and Europe now freeze about nine days later and thaw 10 days earlier than they did a century ago.
Most scientists believe the only effective strategy to halt global warming is to drastically reduce emissions of powerful air pollutants like carbon dioxide, which accounts for two-thirds of all greenhouse gases. In the last 150 years, the surging use of fossil fuels coal, oil, and natural gas -- has released 270 billion tons of carbon into the air in the form of carbon dioxide. Fortunately, oceans, plants, and soils absorb more than half of all atmospheric carbon dioxide -- without them world temperatures might have already soared at an alarming rate.
Which of the following is listed as being evidence for global warming?
选项
A、Water shortages in cities.
B、Earlier thawing of lakes and rivers.
C、Increased levels of greenhouse gases.
D、The rapid extinction of the polar bear.
答案
B
解析
属事实细节题。第三段告诉我们,河流湖泊提前解冻属于全球变暖的迹象。
转载请注明原文地址:https://kaotiyun.com/show/Ik87777K
0
大学英语四级
相关试题推荐
A、Hewantstheotherstofollowhim.B、Hemuststudytheanimalshecaught.C、Hewillcatchupwiththemlater.D、Heisbehindi
Tothecasualobserverwhotravels,themostvisibletravelandtourismindustryemployeesarethoseholdingentry-leveljobsin
ThepartnershipbetweenhumansandanimalsdatesbacktothefirstdomesticationofanimalsintheStoneAge,aslongas9,000y
ThepartnershipbetweenhumansandanimalsdatesbacktothefirstdomesticationofanimalsintheStoneAge,aslongas9,000y
A、BecauseitishigherthantheincomeoftheaverageAmericanfamilies.B、Becausefarmershavelittlemoneyleftafterpayinga
A、Lightnessofmovement.B、Beautifulscenery.C、Freeexpression.D、Enthusiasticmusic.C答题的关键是把握文中的一个过渡句,Sohowwasthismodern
A、Twotofourmonths.B、Aboutthreeweeks.C、Atleasthalfayear.D、Twoyearsormore.D
TherearemanyreasonswhyfamilylifeinBritainhaschangedsomuchinthelastfiftyyears.The【B1】______ofwomenintheearl
A、Tofindoutifhehastheflu.B、Tofindouthowtomaintainanutritiousdiet.C、Tofindouthowtopreventillness.D、Tofin
Theoldfashionedgeneralstoreisfastdisappearing.Thisis,perhaps,apity,becauseshoppingtodayseemstolackthatperson
随机试题
骨盆骨折特有的临床表现是
A.慢性龈炎B.妊娠期龈炎C.急性龈乳头炎D.坏死性溃疡性龈炎E.药物性牙龈肥大牙龈一般不易出血的是()
A、三金片B、肾炎四味片C、癃闭舒胶囊D、癃清片E、五苓散某男,28岁。患慢性非细菌性前列腺炎,症见小便短赤、淋沥涩痛、尿急频数。证属肾虚湿热下注,治疗宜选用的中成药是
各单位每年形成的会计档案,都应由会计机构按照归档的要求,负责整理立卷,装订成册,编制()。
在风险偏好设置与实施过程中,需要注意()。
甲商贸有限责任公司董事会正在讨论设置总经理的有关事项,各董事的下列观点中,符合公司法律制度规定的有()。
在矩阵图法中,按矩阵图的型式可将矩阵图分()。
中国第一大淡水湖是()。
新材料按其性能分,有结构材料和()材料两类。
下面不属于教育心理学研究范畴的是
最新回复
(
0
)