短語詞組短語chemical constituents constituent 化學成分chemical trace constituent 化學痕量成分precipitation chemical constituent 降水化學組成chemical constituent analysis 成分分析characteristic chemical constituent 特征性化學成分analysis of chemical constituent 化學成分分析Newly added chemical constituent 新增成分chemical constituent change 化學成分的變化main chemical constituent 主要化學組分 返回 chemical constituent