And he actually did this in the late 1800's, back before even all of the elements that we know today were discovered, really only about 60% or so, 70% were discovered then that we now know today.

他最终在十九世纪晚期完成了这一壮举，难能可贵的是,虽然我们现在已经发现了所有的元素，但在当时已知的元素只有我们现在知道,百分之六七十，在这种情况下。

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