Scientists have wondered about mysterious dark matter particles for more than seventy years.

VOA: special.2009.07.21

Five hundred years ago, that wouldn't have sounded dark.

五百年前,这个听起来绝对不阴暗

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Another characteristic of these years, which scholars refer to as the Dark Ages, just as they do the years after the fall of the Roman Empire-- dark for two reasons. Dark, in the most obvious way, because we don't have any writing, no record of them.

这也是这段时期的另一个特征,学者们称之为,黑暗时代,他们也是这么称呼,罗马帝国陷落后的那段时期的,称黑暗主要有两个原因,黑暗,最明显的理由,是因为我们没有任何关于他们的史料和记录

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