The Earth saw a considerable loss of atmospheric oxygen at that time.

当时地球大气中的氧气开始大量流失。

But about 300 million years ago, Earth's atmospheric oxygen levels spiked.

但是大约 3 亿年前，地球大气中的氧气含量飙升。

But about 300 million years ago, Earth’s atmospheric oxygen levels spiked.

以蜻蜓而言 在那个时代可以长得跟现在的老鹰般大 而马陆甚至可以长到如同双人橡皮艇般。

During prehistoric times, two-foot dragonflies did exist, because atmospheric oxygen levels were higher.

在史前时代，因为大气中的氧气含量较高，所以两英尺长的蜻蜓确实存在。

All in all, if you can hold your breath for 5 seconds, then you'll most likely survive the atmospheric oxygen apocalypse.

总之，如果你能屏住呼吸5秒，那么你就很有可能在大气氧气大灾难中幸存下来。

If we first look at the loss of atmospheric oxygen as in oxygen in the air, you may not want to be traveling.

如果我们先看看大气中的氧气，比如空气中的氧气，你或许再也不会想去旅行。

The levels of atmospheric oxygen started to plummet -- why, we're not sure.

大气中的氧气含量开始下降——为什么，我们不确定。

The result was an all-time high in the world's levels of atmospheric oxygen.

结果是世界大气中的氧气含量达到了历史最高水平。

You might say, okay, well, just be more careful about specifying the objective— don't forget the atmospheric oxygen.

你可能会说，好吧，好吧，只是在指定目标时更加小心——不要忘记大气中的氧气。

Unlike other possible biosignatures such as atmospheric oxygen, methane is one of the few gases that could be detected by using the James Webb Space Telescope.

与大气中的氧气等其他可能的生物标志不同，甲烷是少数几种可以通过詹姆斯·韦伯太空望远镜探测到的气体之一。

Take the Great Oxygenation Event of 2.3 billion years ago: evidence from ancient rocks tells us that levels of atmospheric oxygen spiked around this time, poisoning the oxygen-hating microbes that had dominated Earth for well over a billion years.

看看 23 亿年前的大氧化事件：古代岩石纪录显示，大气层中氧气含量在此时飙高，毒死了厌氧的微生物，它们已经称霸地球超过十亿年。

While two fifths of thestudents provided the information that the rainforests provide oxygen, in some casesthis response also embraced the misconception that rainforest destruction wouldreduce atmospheric oxygen, making the atmosphere incompatible with human life onEarth.

虽然有 2/5 的学生提到热带雨林能够提供氧气，但是在某些情况下，这一回答也包含着一些误解，例如他们认为热带雨林的破坏会导致大气层氧气减少，从而使大气层不适于地球上的人类居住。