The world today teems with life.
如今,我们的世界生机盎然。
Wherever you look, something is alive.
随处可见活着的生灵。
Then imagine 95% of all this dying in one go.
那么请想象一下所有生命的95%在一瞬间遭到了毁灭。
It's not a fantasy.
这不是虚构的故事。
It did happen 250 million years ago.
它确实发生过,就在2亿5千万年前。
It was the day, the earth nearly died.
那天就是地球劫难日。