human前要加a吗?

a human being a human kind Human life like a poem human 英语翻译Honoring Human Dignity and Altruism From a human science 英语翻译可以这样吗“I waitting a human He in a farture”? human being有同义词吗? human是集合名词吗? 请问human,humans,human being,human beings它们有什么区别以及他们可以通用吗? such a silly earth human求翻译 health is a basic human need anyhow,i have a heart of human Beacuse you a human,not the God!