We speak a decimal language because an ancestral tongue, proto-Indo-European, was decimally based.
我们说的是十进制的语言，这是因为我们的始祖语言——原始印欧语——是基于十进制的。
2
The scholars referred to that source language as Proto-Indo-European. Proto-Indo-European is a reconstructed language.
学者们把这种源语言称为原始印欧语。原始印欧语是一种重建的语言。
3
Proto-Indo-European is a reconstructed language, meaning, it is what linguists concluded a parent language of Sanskrit, Latin and Greek would have to be like.