旧石器时代的生活

Paleolithic man───旧石器时代的人

Paleolithic men───旧石器时代的人

Neolithic Age───新石器时代

Palaeolithic man───早期人类

Palaeolithic men───早期人类

Paleolithic───adj.旧石器时代的

political life───政治生活

Palaeolithic───adj.旧石器时代的；n.旧石器时代

aclinic line───[地理]无倾线

Several theories have been advanced to explain the mystery of the shrinking brain. One is that big heads were necessary to survive Upper Paleolithic life, which involved cold, outdoor activities.───部分古生物学者还是这样分析脑容量缩小的原因的，他们认为在旧石器时代中，古代人类可能需要在复杂的环境下生存，比如大量咬嚼大块食物（野兔、狐狸、马匹等）、从而直接锻炼了脸部、甚至脑部的发达，另外，脑容量越大、适应野外寒冷环境的能力更强。

One is that big heads were necessary to survive Upper Paleolithic life, which involved cold, outdoor activities.───一个认为，由于旧石器时代晚期气候寒冷，需要户外活动的原因，有一个大脑袋是必须的。

One is that big heads were necessary to survive Upper Paleolithic life, which involved cold, outdoor activities.

Several theories have been advanced to explain the mystery of the shrinking brain. One is that big heads were necessary to survive Upper Paleolithic life, which involved cold, outdoor activities.