基本解释道牀層英汉例句雙語例句The basical features of sand hazard along the railway are eroding ballast, covering track and wearing equipments in desert and semidesert areas.荒漠、半荒漠地帶鉄路沙害的基本特征是沙侵道牀、埋沒軌道、磨蝕設備。ballast covering更多例句词组短语短語ballast t covering 道牀層ballast covering更多词组专业释义土木建築工程道牀層