Translation of "humans" into Chinese

Only two things are infinite, the universe and human stupidity, and I'm not sure about the former.

世界上只有两个东西是无限的,一为宇宙,一为人类的愚蠢,我所不能肯定的乃是前者。

People used to think that only humans could use language.

以前人們以為只有人類才懂得用語言溝通。

We believe in life and in the celebration of all that is human and decent.

我们相信生命,相信对一切具有人性而高尚的事物的赞美。

Traditional values had, to a large extent, served as the source of the current understanding of human rights and freedoms.

传统价值观在很大程度上是现代人认识人权和自由的根源。