The countries bordering the Polar Sea have clear responsibilities towards the region, and by implication should view exploiting it for energy as a last resort.

斯塔·豪特指出：“北冰洋周边的国家对这片区域有明确的责任，这里应作为能源开发的最后领域。”

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An instant, suspended in the night... only clear during winter solstice in the heart of a polar night.

这促发的瞬间……只显现于冬至的极夜时分。

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Before middle age of 1970s, area and intensity index of northern polar vortex trend to rise, with small fluctuating, and after that, with clear undulating, it trend to minish.

上世纪70年代中期之前极涡面积、强度基本为上升阶段，之后为下降阶段。

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But now it is clear that not all polar bears return to land.

BBC: Polar bear sanctuary on iceberg

Nasa spokesman Don Savage said they were not clear about what caused the Mars Polar Lander to disappear as it approached the Martian surface and rejected the earlier claims of a cover-up.

BBC: You are in: Sci/Tech

Jason Roberts was making The Polar Bear Family and Me, in which bears were filmed from a clear plastic hide.

BBC: film 'disturbed polar bears'