砂矿开采,Placer dredging,在线英语词典,英文翻译,专业英语2022-08-24
It can be concluded that: First,primary deposit and placer deposit are two main deposits in this origin;Second,the primary deposit formed at hydrothermal stage and mesothermal stage between Presinian and Cretaceous;Third,the feature of ore body is wide and scattered on distributing,small on scale;Four,the storage capacity of the crystal is very abundant,its
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