The leatherback accomplishes this by arranging the blood vessels in the base of its flipper into a countercurrent exchange system.

棱皮龟通过将鳍状肢底部的血管排列成逆流交换系统来完成这一过程。

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Yet it's the bottom section of the lungs that contains the warmest and wettest blood vessels - the most efficient for gas exchange and moving oxygen into the blood.

但正是肺的底部含有温度最高、血流量最大的血管，最频繁的气体交换在这里进行，将氧气运送到血液中。

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These districts are traditionally famous for the exchange of commodities, which were brought in by Arabian cargo vessels known as dhows from east Asia.

这些地区以前是以商品交换而闻名的，这些商品是由阿拉伯的货轮dhows(独桅三角帆船)从东亚运来的。

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The Coast Guard also has a database, known as the U.S. Coast Guard Maritime Information Exchange, with inspections and any deficiencies found aboard ships, dating to when the vessels entered service.

NPR: No Central Agency Oversees, Inspects Cruise Ships