And that gas reduces the iron oxide to iron.

这种气体让氧化铁转化为铁。

I sampled bacteria at Blood Falls, a natural phenomenon of a subglacial pond spurting out iron oxide that was thought to be utterly lifeless until a little more than a decade ago.

我在 Blood Falls 采集了细菌样本，这是一种冰下池塘喷出氧化铁的自然现象， 直到十多年前， 氧化铁才被认为完全没有生命。