短語(yǔ)詞組短語(yǔ)sand gravel extraction 採(cǎi)砂sand and gravel extraction 砂石精選effects of sand extraction 採(cǎi)砂影響extraction sand in river course 河道採(cǎi)砂excessive extraction of sand 無(wú)序採(cǎi)砂 返回 sand extraction