砾石

• Granite , pottery , pebble , water scope
  花岗岩烧陶砾石水景
• Infixion method used in gravel
  砾石层中适宜选用的钻进方法
• Drilling gravel formations in the western area : challenges and solutions
  西部地区砾石层钻井难点及对策
• Baffled gravel - placement device
  装有隔板的砾石充填装置
• The larger reverse circulation bits used for drilling through pebbles
  卵砾石层大直径反循环桩孔钻进用钻头
• Aggregates for railway ballast
  铁道砾石用集料
• Study of blasting techniques of frozen gravel stratum in vertical well tunneling
  立井掘进冻结砾石层爆破技术初步研究
• Assorted sand and gravel
  筛选的砂和砾石
• Sand and gravel washer
  砂及砾石洗涤器
• Bulk volume of gravel
  砾石的充填体积