More than60 pits in old mining areas are being extended.
的六十多个矿井正在扩建。
More than 60 pits in old mining areas are being extended.
老矿区的六十多个矿井正在扩建。
Mining under village in a scientific and rational way is an important issue for boosting economic and social benefits for new and old mining areas;
科学合理地开采村庄下压煤是新老矿区提高经济、社会效益的重要问题，也是煤矿开采技术中探讨的重要理论和实践问题。
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