4 Although at present we have no way of knowing for sure whether or not human languages can be traced back to the same root, they all go back to the dim uncertainty of prehistory.
4 Although at present we have no way of knowing for sure whether or not human languages can be traced back to the same root, they all go back to the dim uncertainty of prehistory.
4尽管目前我们还无确定人类的语言是否同宗同源，但是它们都可追溯到朦胧的史前时期。