它被一次短暂的变暖过程打断，也就是间冰段，这个过程只持续了几千年。

It was interrupted by brief warmings – interstadials – none of which lasted more than a few thousand years.

youdao

然后，非常突然地，不到两万年前，间冰段结束，很快，冰冻几乎就消失了。

Then, quite suddenly, less than 20, 000 years ago, an interstadial began to run away with itself and, quite soon, the icy shroud was almost gone.

youdao

然后，非常突然地，不到两万年前，间冰段结束，很快，冰冻几乎就消失了。

Then, quite suddenly, less than 20,000 years ago, an interstadial began to run away with itself and, quite soon, the icy shroud was almost gone.

youdao