Without water one might not expect to find any caves, 没有水的地方似乎不可能有洞穴
lies one of the longest, deepest and most surprising caves in the world. 存在着一座世界上最长、最深 也最令人惊奇的洞穴
that one would not expect it to contain any life whatsoever. 不管什么生物似乎都不可能在那里生存
And the Belizean white crab is another creature that is unique to just one cave system. 而伯利兹白蟹是另一个 洞穴生态系统中的特有物种
like the remiped, one of the most ancient of all living crustaceans. 例如桨足虫——一种最古老的甲壳动物
one might not expect to find plants. 似乎不太可能会有植物
500 years ago they supported one of the world's great civilisations 500年前 它们维系着 一个世界上最伟大的文明
It takes more than 30 days to complete one. 每个燕窝得花上30多天才能完工
It's a remarkable skill and one we still do not fully understand. 我们至今仍未能完全了解 这种了不起的本领