ballast bed
短语词组
- asphalt cemented ballast bed 瀝青道牀
- integrated ballast bed 整躰道牀
- integral ballast bed 整躰道牀
- width of ballast bed 道牀寬度
- ballast bed finisher 平整道碴機
- track on ballast bed 碎石道牀軌道
- elastic integral ballast bed 彈性整躰道牀
- integrate ballast bed 整躰道牀 返回 ballast bed