听力文本

And when sulphuric acid dissolves limestone, it leaves behind gypsum,
硫酸在溶解石灰岩的同时，也留下了石膏，
the basis of Lechuguilla's remarkable formations.
它们最终形成了龙舌兰洞的奇景
And there was one set, more than a mile from the surface, that almost defied belief.
这里有一组景观，位于地表之下1英里多的地方，美得简直无法令人相信。
The Chandelier Ballroom was the ultimate discovery.
“灯饰大厅”是最后被发现的厅洞
With its six-metre-long crystals, it's surely the most bizarre cave chamber in the world.
这里尽是6米多长的结晶群，它可以说是世界上最奇异的厅洞。
And the walls had one further surprise.
而石壁上还有更惊人的发现
Extremophile bacteria were found to be feeding on the rock itself.
嗜极细菌在岩壁上自我生长

The discovery of life that exists without drawing any of its energy from the sun
生命彻底脱离太阳能量，却依然生存的现象
shows us once again how complex and surprising the underground world can be.
再一次向我们展示了地底世界是多么的复杂和惊人
Each year, explorers chart over a hundred miles of new cave passages.
每年，探险家们都会测绘上百英里新的洞穴通道
But with half the world's limestone still to be explored,
但世界上仍有一半石灰岩洞尚未被开发
who knows how many Lechuguillas are still waiting to be discovered?
谁知道还会有多少个龙舌兰洞等着人们去发现呢？

视频及简介

洞穴是不受阳光控制的生物栖息地之一，但这并不意味着那里就不存在野生生物。本集节目将深入洞穴内神秘而永恒的黑暗，探索山洞、洞穴和隧洞中未知的地下世界。