人类的单词怎么拼

　　海豹的鳍肢与人类的手臂同源。

　　The seal's flipper is homologous with the human arm.

　　科学家不断扩大人类知识的范围。

　　Scientists continue to push back the boundaries of human knowledge.

　　科学家已告诫人类慎重对待这项技术。

　　Scientists have sounded a note of caution on the technique.

　　需要交流是人类社会最重要的一个特征。

　　The need to communicate is a key characteristic of human society.

　　她毕生探索人类心灵的奥秘。

　　She spent her life plumbing the mysteries of the human psyche.