Paleolithicman could only make the most basic stone tools.
旧石器时代的人类只能制造最简单的石器。
2
Paleolithicman waited by caves for the realization of why he was there, and hunted;
旧石器时代的人在洞中等待明白他为什么在那儿，并且打猎；
3
The gradual-adaptation principle is deeply rooted in human physiology, and has worked for about a billion runners since Paleolithicman started stalking wild animals in East Africa 150,000 years ago.