So the establishing of(horizontal) control datum with appropriate precision standards systematically is the precondition to make sure the precision of ballastless track laying.

系统建立适宜精度标准的平面控制基准，是保障无碴轨道铺设精度指标顺利实现的前提。

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So the establishing of(horizontal) control datum with appropriate precision standards systematically is the precondition to make sure the precision of ballastless track laying.

系统建立适宜精度标准的平面控制基准，是保障无碴轨道铺设精度指标顺利实现的前提。

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