短语词组短語road -rail level crossing 鉄路平交道口level rail 水平尺level rail transport 武漢軌道交通longitudinal level of rail 軌道前後高低;前後高低longitudinwouls level of rail 軌道前後坎坷longitudining level of rail 軌道前後高卑Level slipping rail 水平滑軌 返回 rail level