The oldest of these, as far as we know, was the Indo-European family of languages, which were beginning to be spoken clear back during the Stone Age.

据我们所知，其中最古老的语言是印欧语系。 远在石器时代人们就开始使用印欧语了。

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The oldest of these, as far as we know, was the Indo-European family of languages, which were beginning to be spoken clear back during the Stone Age.

据我们所知，其中最古老的语言是印欧语系。 远在石器时代人们就开始使用印欧语了。

youdao