A.1Cr17 B.1Cr18Ni9Ti C.聚四氟乙烯 D.SiO2
A.ZAlSi12 B.2A50(舊牌號(hào)LD5) C.ZAlMg10 D.2A12(舊牌號(hào)LY12)
A.1Cr13鋼 B.1Cr17鋼 C.3Cr13鋼 D.4Cr13鋼