基本解释道床层英汉例句双语例句The basical features of sand hazard along the railway are eroding ballast, covering track and wearing equipments in desert and semidesert areas.荒漠、半荒漠地带铁路沙害的基本特征是沙侵道床、埋没轨道、磨蚀设备。ballast covering更多例句词组短语短语ballast t covering 道床层ballast covering更多词组专业释义土木建筑工程道床层