短語(yǔ)詞組短語(yǔ)piston ventilation shaft layout 活塞風(fēng)井設(shè)置ventilation of mine shaft 鑛井通風(fēng)south ventilation shaft 南風(fēng)井surface mine ventilation shaft 地麪風(fēng)井uranium mine ventilation shaft 鈾鑛井通風(fēng)emergency ventilation shaft 事故通風(fēng)井a ventilation shaft 排氣孔tunnel l ventilation shaft 隧道通風(fēng)井ventilation shaft reconstructing 風(fēng)井改造 返回 ventilation shaft