Discusses the selection line methods of convey coal pipe of long distance, from the angles of selection line principle, and the basic data to collect, etc.
本文从选线的原则、选线需搜集的基础资料等角度，论述了长距离输煤管道线路的选线方法。
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This method explained how to program using a trade line at long distance and explained the basic theory of communication.