proof silver造句

例句与造句

1. Standard practice for proof silver corrections in metal bearing ores , concentrates and related materials by fire assay gravimetry
   用火试金重量分析法验证含金属矿物浓缩物及相关材料中银修正值的标准实施规范
2. It's difficult to find proof silver in a sentence. 用proof silver造句挺难的