自然选择褪去了厚厚的毛发，但是却把背后的控制机制留了下来。

Natural selection removed the thick hair but left behind the mechanism for controlling it.

youdao

自然选择褪去了厚厚的毛发，但是却把背后的控制机制留了下来。

Natural selection removed the thick hair but left behind the mechanism for controlling it.

youdao