单项选择题
A.1:200~1:400 B.1:200~1:500 C.1:300~1:500 D.1:200~1:700
A.擦洗 B.多步清洗法 C.加热浸洗 D.浸—喷联合清洗
A.冷拉圆钢 B.冷拉优质型钢 C.热轧扁钢 D.热轧优质型钢