A. always the same size in all alloys B. a single crystal ofmetal as seen in the metal"s microstructure C. can be removed from metals by treating them with methyl methacrylate D. used to be called a"polytip"
A. 较昂贵的合金 B. 合金中一种或几种贵金属元素含量不小于25%的合金 C. 合金中一种或几种贵金属元素含量不小于15%的合金 D. 在口腔环境中耐腐蚀的合金
A. 低电导率 B. 中等的密度 C. 高弹性模量 D. 低断裂韧性