The Living Seas The ocean covers three quarters of the earth’s surface, produces 90 percent of all its life-supporting oxygen, a

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问题 The Living Seas
The ocean covers three quarters of the earth’s surface, produces 90 percent of all its life-supporting oxygen, and is the driving force behind the entire weather system. There are over 450 million cubic miles of sea water on the earth; and each cubic mile contains over 150 million tons of minerals.
So vast and so pervasive is the sea that if the earth’s crust were made level, ocean water would form a blanket over 8,000 feet deep.
The oceans contribute immeasurably to the earth’s life support system as well as provide an untapped storehouse of food, minerals, energy, and archaeological treasure.
Advanced atmospheric diving suits permit researchers to descend to depths of 1, 500 feet. Yet the ocean’s average depth is greater than 12,000 feet. It is at these depths that remarkable discoveries are being made, discoveries which only a short time ago would have been impossible.
In that depth, where darkness is absolute and pressure exceeds eight tons per square inch, robotic submersibles have discovered enormous gorges, four times deeper than the Grand Canyon. Here, too, are volcanoes that vastly outnumber those on land. Landslides the size of Rhode Island have been recorded, as well as raging undersea storms that go completely unnoticed on the surface while dramatically rearranging the underwater landscapes.
And under these seas the largest single geological feature on earth has been found—a mountain range that dwarfs the Himalayas. It’s a range that covers nearly one quarter of the earth’s surface.

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答案 富有生命的海洋 海洋覆盖了地球表面的四分之三,地球上维持生命的氧气,90%来自海洋,海洋也是整个天气系统变化的动力。地球上的海水超过45亿立方英里,每立方英里蕴藏的矿物质超过了15亿吨。 海洋是如此浩瀚无边,遍布全球,地球的地壳若是整成平的,海水将会形成一个8 000英尺深的覆盖层。 海洋对地球的生命保障系统发挥着不可估量的作用,还是一座尚未打开的宝库,藏有食物、矿产、能源以及考古宝藏。 先进的充气潜水服可以让研究人员潜到1 500英尺的地方。但海洋平均深度超过12 000英尺。就是在这个深度下才有了许多举世瞩目的发现,要是放在不久之前,根本是不可能的事情。 在那个深度,海里都漆黑一片,每平方英寸的压力超过了八吨,潜水机器人还发现了许多巨大的峡谷,比科罗拉多大峡谷还要深3倍。这里也有数量巨大的火山,比陆地上多得多。有记录发现了规模有罗德岛那么大的滑坡,还有狂躁的海底风暴,虽在海面上平静如初,却剧烈地改变着海底的风景地貌。 在海底还发现了地球上最大的单体地质构造——是一个直接傲视喜马拉雅山的山脉。这个山脉跨越了几乎地球表面的四分之一。

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