首页
登录
职称英语
Spring is usually prime food time for some 1,200 polar bears along Canada’s
Spring is usually prime food time for some 1,200 polar bears along Canada’s
游客
2024-02-23
14
管理
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. [br] 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://tihaiku.com/zcyy/3476667.html
相关试题推荐
TheH5N1virusdoesnotusuallyinfecthumans.In1997,however,thefirstc
TheH5N1virusdoesnotusuallyinfecthumans.In1997,however,thefirstc
TheH5N1virusdoesnotusuallyinfecthumans.In1997,however,thefirstc
TheH5N1virusdoesnotusuallyinfecthumans.In1997,however,thefirstc
BasictoanyunderstandingofCanadainthe20yearsaftertheSecondWorld
BasictoanyunderstandingofCanadainthe20yearsaftertheSecondWorld
BasictoanyunderstandingofCanadainthe20yearsaftertheSecondWorld
BasictoanyunderstandingofCanadainthe20yearsaftertheSecondWorld
Beforerefrigerators,homesusuallyhadiceboxes.But【S1】______waytokeep
Beforerefrigerators,homesusuallyhadiceboxes.But【S1】______waytokeep
随机试题
Whateffectdoesjoblessnessandcutsinpublicassistancehaveonchildrenofs
You’dbetterremainhere,______?A、hadn’tyouB、shouldn’tyouC、couldn’tyouD、wo
Lonelinesshasbeenlinkedtodepressionandotherhealthproblems.Now,as
某互联网单位组织体检发现,员工糖尿病的患病率较高,约有10%左右的员工检查患有糖
下列属于犯罪中止的是()。A.已经着手实行犯罪但犯罪未发生 B.在犯罪
小李在甲银行研究部门工作,但他准备辞职,辞职后可能到乙银行类似部门工作,则下列做
依据我国宪法的规定,非法拆阅邮件或窃听公民电话等通讯内容的行为是侵犯公民的()
社会工作者谢军发现他所在的社区内老人居多,允其是独居老人。,谢军服务机构组织为独
中风先兆的舌态是( )。A.舌短 B.舌痿 C.弄舌 D.吐舌 E.舌
下列选项中属于条件反射的是()。 (A)马戏团里驯兽员给大狗熊一个皮球
最新回复
(
0
)