As far as we know, such a magneticreversal doesn't cause any harm to life on Earth.
就我们所知道的，这种磁极转换不会对地球上的生命造成任何伤害。
2
Although magnetic reversals have occurred many times in the geologic past, it is not yet possible to predict when the next reversal will occur.
尽管在过去地质时期地磁场发生了多次倒转，但要预测下次倒转将在何时发生也还是不可能的。
3
They claim a relationship between the rotation and the magnetic polarity of Earth, which does change irregularly, with a magneticreversal taking place every 400,000 years on average.