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冲击钻井

226 bytes removed, 05:15, 13 October 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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