Human being 什么时候加S

look like human beings 中为什么不是humans,being为什么还要加s human being前面要加the吗 human,human being human being里的这个BEING是什么用法?现在分词?动名词?为什么非要加个being 如果human相当于中文 What’s your opinion on relationship between human being and 英语语法 Hemingway's enduring contribution to the human being is What's the relationgship between nature and human being human being还是human beings? human being和human加的谓语用单数还是复数? 为什么human加s构成复数形式 human复数要加S吗? human being指人类