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Manatees are born underwater and never leave it-though they must surface to breathe every few minutes .

海牛是在水下出生的，尽管它们需要隔几分钟探出水面做个呼吸，但是它们一辈子不会离开那里。

Many are large animals , such as rhinos , tapirs , elephants , dugongs and manatees .

它们中的许多都是大型哺乳动物，比如犀牛、貘、大象、儒艮和海牛。

Sailors of old sometimes mistook manatees for mermaids , which shows how months at sea quaffing rum and missing female company can cloud one 's vision .

古时的水手曾误把海牛认作美人鱼，实可说明数月在汪洋大海上豪饮朗姆，缺乏女性陪伴的生活是如何让人严重眼花。

For instance , how terrestrial mammals moved back into the water and evolved into whales , seals and manatees continues to puzzle fish and colleagues .

例如，陆地哺乳动物如何回到水中，进化成鲸鱼、海豹和海牛呢？这一问题一直让fish和他的同事困惑不解。

I had often watched manatees in these warm coastal waters , but I 'd never seen one act like this before .

在这片温暖的海域，我经常看见海牛，但是从没见过它们有这么怪异的举动。