单项选择题
A.钢带 B.角钢 C.槽钢 D.H型钢
A.型钢 B.多用钢 C.冷轧钢 D.热轧钢
A.0.45% B.4.5% C.45% D.0.045%
A.特殊镇静钢 B.半镇静钢 C.镇静钢 D.沸腾钢
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