A.1%~5% B.5%~10% C.0.1%~0.5% D.0.5%~1%
A.鋁和銅B.銅和鉻C.鋁和鎳D.鉻和鎳
A.合金結(jié)構(gòu)鋼 B.優(yōu)質(zhì)碳素鋼 C.普通鋼 D.鑄鐵