短語詞組短語placer -gold 砂金placer r gold 砂金placer gold deposit 砂金礦床littoral placer gold 濱海砂金成paleo -placer gold 古砂金placer gold sample 砂金樣品placer gold structure basin 砂金構(gòu)造盆地placer gold metallogeny 砂金成礦the placer gold deposit 砂金礦體 返回 placer gold