听力文本

Three long, slow phases, sprawled over at least 80,000 years,
3个漫长缓慢的过程总共延续了8万年之久，
very different from how the meteor theorists had seen it.
与先前的天体碰撞论大相径庭。
Yet Wignall was still no closer to understanding why it had happened or what the killer was, but he had found a clue.
然而Wignall仍旧无从得知事情发生的原因以及杀手的真实身份，不过他找到了线索。
Analysis of the rock showed that just after the marine extinction,
岩石的分析结果表明，就在海洋生物大灭绝刚刚结束，
but before the final death of everything on the land,
陆地生物的最后大灭绝即将开始之前，
there was a mysterious increase in a form of carbon, called carbon 12.
碳元素的一种同位素碳-12，出现奇怪的数量激增现象。
This is normally produced by rotting plant and animal matter,
它通常产生自腐烂的动植物，
but this was a huge increase, too big to be explained by that alone.
不过此次激增数量巨大，单凭这一点并不足以解释。

Wignall realized that here was a fresh piece of evidence,
Wignall意识到这是一条新的证据，
something that, if he could understand it might provide the key to the Permian riddle.
如果能对此作出解答，或许就能获得解开二叠纪之谜的密钥。
The carbon 12 increase is clearly telling us something.
碳-12的猛增显然包含了一些事实。
It's a clue to the nature of the Permian extinction.
它是了解二叠纪生物大灭绝真相的线索。
There's something mysterious going on at this time, but exactly what it is not immediately apparent.
这段时期发生了一些神秘的事，但它们究竟是什么并不是一眼就能看出来的。

视频及简介

如今，我们的世界生机盎然，随处可见活着的生灵。那么请想象一下所有这些生命有95%在一瞬间遭到了毁灭。这不是虚构的故事，它确实发生过。就在3亿年前的二迭纪，地球上还是一片丰饶繁荣的景象，然而2亿5千万年前的一场神秘事件导致了95%的物种灭绝，称为二迭纪生物大灭绝。这个凶残的杀手究竟是谁？是剧烈的地质运动、气候灾变，还是来自外太空的天体碰撞？为此，科学家们展开了一系列调查，试图解开“地球劫难日”惨剧背后的真相。