Stoplights are red, yellow, and green, because traffic officials, early on copied the code system railroad engineers devised for track systems controlling the trains.

交通信号灯采用红、黄、绿三种颜色，是因为早期的交通指挥官模仿铁路工程师所设计的用于铁道系统控制火车的编码系统。

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Can you imagine the individuals who make flat cars and rails and railroad engines and who construct and install the communication systems incidental thereto?

你可以想象一下那些操作平板车、钢轨和机车还有设计和构建交通运输系统的人们吗？

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The training system for train dispatchers is one of the most typical systems in the curriculum of railroad transportation students.

铁路列车调度员培训模拟系统是铁道运输专业课程教学实践环节的典型系统之一。

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Al Qaeda has long studied the possibility of attacks on railroad systems, seeing them as cheap, relatively easy to carry out and with potentially devastating results.

CNN: Suspects in thwarted terror plot to appear in court

Al Qaeda has long studied the possibility of attacks on railroad systems -- seeing them as cheap, relatively easy to carry out and with potentially devastating results.

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Despite lethargic railroad systems, Ruby on Rails was mile-a-minute.

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