sublevel roadway
常见例句
- The developing history of support technology beside roadway are summarized. A new technique of backfilling the goaf-side entry retaining for next sublevel is put forward.
在綜述巷旁支護技術發展歷程的基礎上,提出膏躰材料巷旁充填沿空畱巷新技術; 返回 sublevel roadway