During some periods, the bottom layer of the world's oceans comes from cold, dense water sinking in the far North Atlantic.

在某些时期，世界海洋的底层来自遥远的北大西洋下沉的寒冷、稠密的水。

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With warm, buoyant water on top and cold, dense water below, the water column doesn't mix easily.

上层水温暖而浓度小，下层水寒冷而浓度大，因此水体难以混合。

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This causes the dense water from the Mediterranean to flow like a river along the sea bed, carving a channel and deep Banks.

这样就导致了从地中海而来的高密度的水流，沿着海床像一条河那样流动，并刻化出一条通道和深深的海床。

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The obvious solution getting people to breathe hydrogen cannot work either, because a lungful of hydrogen gas, being less dense than water, contains less hydrogen, and so would produce too weak an image.

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As my eyes adjusted, I realized that this seemingly solid carpet of green was actually a large, dense grouping of water hyacinth, throbbing with electric blue and crimson dragonflies, spindly mottled spiders and monstrous ants.

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But they did more than just survive in the grass green water, dense with algae and other substances, known and unknown.

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