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冲击钻井

204 bytes added, 11:59, 23 September 2015

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===成本===

For cost comparisons between hand drilling and percussion drilling: [http://www.wellspringafrica.org/WebManual/costcomp.htm Wellspring Africa's Hand Powered Percussion Drill] illustrates costs for materials, tools, and labour.如果想比较人工挖掘井与冲击钻井的成本，请点击：[http://www.wellspringafrica.org/WebManual/costcomp.htm 非洲泉源组织手动冲击钻井]阐明了材料、工具和人力成本。

===实地经验===

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