A.2mg/kg,5mg/kgB.1mg/kg,3mg/kgC.1mg/kg,5mg/kgD.2mg/kg,10mg/kg
A.99.9%B.99.99%C.99.999%D.99.9999%
A.化學(xué)純B.分析純C.優(yōu)級(jí)純D.色譜純