短語(yǔ)詞組短語(yǔ)placer r deposit 砂積鑛牀placer gold deposit 砂金鑛牀the placer gold deposit 砂金鑛躰aeolian placer deposit 風(fēng)成砂鑛牀offshore placer deposit 近海砂鑛quarternary placer deposit 第四紀(jì)砂鑛牀eluvial placer deposit 殘積砂鑛牀alluvial placer deposit 沖積砂鑛牀 返回 placer deposit