人类语言中有几个独特的特征，且在很大程度上是其他物种的交流系统中从未发现的。
There're several features peculiar to human language that have, for the most part, never been found in the communication system of any other species.
因此，大多数数字系统都是两个关键因素的意外结果：人类的语言能力及我们对手和手指的关注倾向。
Most number systems, then, are the by-product of two key factors: the human capacity for language and our inclination for focusing on our hands and fingers.
人类的语言是多产的，是一个开放的交流系统，而其他交流系统都没有这种特性。
Human language is productive, an open-ended communication system, whereas no other communication system has this property.
应用推荐