by nature

It’s unlikely that this gully was produced by nature.

这个溪谷不大可能是自然。

And all this beheath a sky by nature skyless in which the sun sets without setting at all and hides without hiding behind an unminding cloud.

而这一切都是在一个本身没有天空天空下发生，太阳在那一点也不沉落地沉落一点也不隐藏地隐藏在一朵非自愿云。

Tigers are cruel by nature.

老虎生性残忍。

I'm very lazy by nature.

我生性很懒惰。

He is timid by nature.

他生性胆小。

I'm not violent by nature .

我生来并不粗暴。