Exploration programmes are based on drilling for the stratiform deposits along projections of established trends. 勘探計劃依靠鉆探，鉆探層狀礦床沿著(zhù)已知走向的延伸部分進(jìn)行。
In rotary boring, rock penetration is achieved by the rotation of the hollow cutting tool. 旋轉鉆探利用中空的切削工具通過(guò)旋轉鉆透巖石。
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