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
42
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/2860403.html
相关试题推荐
[originaltext]Weusuallythinkofhistoryusthestoryofimportantpeople
[originaltext]Weusuallythinkofhistoryusthestoryofimportantpeople
[originaltext]TheclimateofthewestcoastisthemostmoderateinCanada.
[originaltext]TheclimateofthewestcoastisthemostmoderateinCanada.
StandardEnglishisthevarietyofEnglishwhichisusuallyusedinprintan
StandardEnglishisthevarietyofEnglishwhichisusuallyusedinprintan
StandardEnglishisthevarietyofEnglishwhichisusuallyusedinprintan
StandardEnglishisthevarietyofEnglishwhichisusuallyusedinprintan
StandardEnglishisthevarietyofEnglishwhichisusuallyusedinprintan
StandardEnglishisthevarietyofEnglishwhichisusuallyusedinprintan
随机试题
Althoughcreditcardsarebecomingamore【B1】______partofthefinancials
Scientistssaytheyhavehighhopesforadrugthatcouldonedayprovidean
【B1】[br]【B3】A、constantB、regularC、lastingD、normalC词义辨析题。regular意为“定期的,有规律的”
14岁女孩,发热半个月,体温38~39℃,双手指指关节和掌指关节肿痛伴活动受限,
下列融资需求当中,既有可能通过短期融资实现,又有可能通过长期融资实现的有()。
A.饭前服 B.睡前服 C.饭后服 D.大多宜空腹服 E.不定时服滋补药
左边给定的是纸盒的外表面,下面哪一项能由它折叠而成?
主题班会的主要形式有() A.主题报告会B.主题汇报会C.主题
既解表散热,又疏肝和胃的中成药是A.参苏片 B.小柴胡片 C.板蓝颗粒 D
对某项目进行风险概率估计时,由于没有有效的统计数据,也不能进行试验,则宜采用的概
最新回复
(
0
)