这条河流的源头在远处的山脉中。

The ___origin of this river is in the distant mountains.

尽管他现在很成功，但他从不忘记自己的农民出身。

Despite his current success, he never forgets his ___origins as a farmer.

坐标轴上的原点用字母O标记。

The ___origin of the coordinate axes is marked with the letter O.