Question

WASHINGTON—Two-thirds of the world’s polar bear population could be gone by 2050 if predictions of melting sea ice hold true, the US Geological Survey reported on Friday.

The fate of polar bears could be even worse than that estimate, because sea ice in the Arctic might be disappearing faster than the available computer models predict, the geological survey said in a report aimed at determining whether the big white bear should be listed as a threatened species.

“There is a definite link between changes in the sea ice and the welfare of polar bears,” said Steve Amstrup, who led the research team. He says Arctic sea ice is already at the lowest this year and is expected to retreat(退卻) farther this month.

That means that polar bears—some 16,000 of them -- will disappear by 2050 from parts of the Arctic where sea ice is melting most rapidly, along the north coasts of Alaska and Russia, researchers said in a telephone briefing(簡報).

Other polar bears could survive beyond that date but many of those could be gone by 2100, Amstrup said. By this century’s end, the only polar bears left might live in the Canadian Arctic islands and along the west coast of Greenland.

“It is likely to result in loss of approximately two-thirds of the world’s current polar bear population by the mid 21st century,” the report’s executive summary said.

“Because the observed trajectory(軌跡)of Arctic sea ice decline appears to be underestimated by currently available models, this assessment of future polar bear status may be conservative(保守的).”

In January, the US Fish and Wildlife Service proposed listing the polar bear as a threatened species, noting polar bears depend on sea ice as a platform to hunt seals, their main food.

Without enough sea ice, polar bears would be forced onto land, but they are poor hunters once they get out of the water and ice, the researchers said. The bears’ disappearance would probably take place as young cubs(幼獸)failed to survive to adulthood and females were unable to reproduce successfully.

1.What was the US Geological Survey intended to do?

A．To determine whether the polar bear was in danger.

B．To measure how fast the sea ice melts in the Arctic.

C．To check the predictions of the computer models.

D．To find out the exact number of the polar bear.

2.What causes the polar bears to disappear by 2050?

A．The pollution of the Arctic region.           B．The sea ice melting at high speed

C．Fewer food sources being left.             D．The temperature getting colder.

3.The key to preventing polar bears dying out seems to _______________.

A．help young polar bears to survive the cold winter

B．have large number of seals living in the oceans

C．make sure there is enough sea ice in the Arctic

D．provide chances for adult polar bears to reproduce

 

Answer 1

【答案】

1.A

2.B

3.C

【解析】

試題分析:本文是一篇說明文，說明了美國地質(zhì)專家預測到2050年，海冰融化導致北極熊列為瀕危物種，但是北極熊比預計的更糟，因為在北極海水的消失比電腦預測的更快，地質(zhì)勘察報告旨在確定是否將北極熊列為瀕危物種

1.細節(jié)題，由第二段最后一句the geological survey said in a report aimed at determining whether the big white bear should be listed as a threatened species可以知道答案，故選A。

2.細節(jié)題。由第一段Two-thirds of the world’s polar bear population could be gone by 2050 if predictions of melting sea ice hold true, the US Geological Survey reported on Friday.可以知道答案，所以選B。

3.推理題，由倒數(shù)第二段最后一句noting polar bears depend on sea ice as a platform to hunt seals, their main food.可以推出答案，所以選C

考點：本篇是一篇說明文

點評：做細節(jié)題的關鍵是找出原文的根據(jù)，認真核查題支和原文的異同，常犯錯誤有：絕對化語言，范圍擴大或縮小，以偏概全，張冠李戴等。推斷題測試考生在閱讀基礎上的邏輯推理能力，要求考生根據(jù)文章所述事件的邏輯關系，對未說明的趨勢或結局作出合理的推斷；或根據(jù)作者所闡述的觀點理論，對文章未涉及的現(xiàn)象、事例給以解釋。考生首先要仔細閱讀短文，完整了解信息，準確把握作者觀點。