I take it the claim basically is that, to put it in more familiar language it takes one to know one.

我把那个看做是个断言,基本上是为了,用更熟悉的语言来阐述,只有同类才最了解彼此

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they understand the culture and they know the geography quite well.

他们了解这个国家的文化，并且对地域也很熟悉。

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