A.Q235普通碳素結(jié)構(gòu)鋼A級(jí) B.Q235沸騰鋼 C.Q345低合金結(jié)構(gòu)鋼 D.優(yōu)質(zhì)碳素結(jié)構(gòu)鋼
A.50% B.100% C.75% D.0.8
A.1/3 B.1/2 C.1/4 D.1