单项选择题
A.硫酸和氢氟酸B.硝酸和氢氟酸C.盐酸和氢氟酸D.磷酸和氢氟酸
A.减薄、分料、精加工、开槽B.减薄、分料、开槽、精加工C.分料、减薄、开槽、精加工D.分料、减薄、精加工、开槽
A.沿两轧制面60mmB.沿两轧制面50mmC.沿两轧制面40mmD.沿两轧制面30mm