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
2023-07-22
12
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] Many scientists hold that global warming can be controlled by.
选项
A、reducing the polar bear population.
B、paying more attention to the earth’s rising temperatures
C、reducing carbon dioxide emissions
D、refreezing the polar ice caps
答案
C
解析
属事实细节题。第四段开头指出:“大部分科学家都认为,阻止全球变暖惟一有效的策略就是大量减少排放像二氧化碳这样危害大的空气污染物。”
转载请注明原文地址:https://tihaiku.com/zcyy/2860404.html
相关试题推荐
StandardEnglishisthevarietyofEnglishwhichisusuallyusedinprintan
StandardEnglishisthevarietyofEnglishwhichisusuallyusedinprintan
StandardEnglishisthevarietyofEnglishwhichisusuallyusedinprintan
StandardEnglishisthevarietyofEnglishwhichisusuallyusedinprintan
StandardEnglishisthevarietyofEnglishwhichisusuallyusedinprintan
StandardEnglishisthevarietyofEnglishwhichisusuallyusedinprintan
StandardEnglishisthevarietyofEnglishwhichisusuallyusedinprintan
StandardEnglishisthevarietyofEnglishwhichisusuallyusedinprintan
StandardEnglishisthevarietyofEnglishwhichisusuallyusedinprintan
StandardEnglishisthevarietyofEnglishwhichisusuallyusedinprintan
随机试题
DoestheWorldFaceaFutureofWaterWars?[A]Throughouthistor
[originaltext]HuangYiworksforacompanythatsellsfinancialsoftwareto
【B1】[br]【B3】A、appearanceB、frameworkC、outlookD、structureA词义辨析。framework
网上购物作为一种新的购物方式,近年来在国内被广泛接受,尤其是在年轻人中流行开来。2006年以来,中国网上购物增长速度迅猛。网上购物的特点是购物方式新颖、
A. B. C. D.
超声纵向分辨力是分辨前后两个点最小距离的能力,其理论计算值应是A.λ/4(入波长
凯恩斯认为,人们对货币的需求产生于( )A.经济主体的消费愿望 B.经济主体
共用题干 DomesticViolenceNearlythreein1
在古代印度,能够享受最好教育的是当时的最高种姓()。 A.刹帝利B.吠舍
大型储罐的管道与泵或其他有独立基础的设备连接,应在储罐( )合格后安装。A.充
最新回复
(
0
)