placer mining
短語詞組
- gold placer -mining 采金場
- placer gold mining 砂金礦開采
- placer r mining 砂礦淘采
- beach placer mining industry 海濱砂礦開采業(yè)
- beach placer mining 海濱砂礦開采
- method of littoral placer mining 濱海砂礦開采法
- hydraulic mining of placer 砂礦露天水力開采 返回 placer mining