Offshore drilling platforms extend the search for oil to the ocean's continentalshelves—those gently sloping submarine regions at the edges of the continents.
海底钻井平台将寻找石油的区域延伸到了海洋大陆架——大陆边缘那些平缓倾斜的海底区域。
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This ice is often held in place by shallow ocean bottoms or continentalshelves.
这些冰层常常固定在浅海的海底或者大陆架上。
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Much of the activity between the continentalshelves takes place deep underwater at the mid-ocean ridges.