They started having mail cars on trains and they started having postal sorting on the train.

人们开始用铁路邮政车,并且在火车上分类整理。

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They were speeding the mail so that it didn't have to wait to sort it before it went on the train-- it was sorted while it was moving on the train.

发信速度很快,以致于在上火车之前不再需要,等着分类整理-,可以边坐火车边整理。

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