单项选择题
A.废钢熔化B.脱硫C.脱磷D.脱碳
A.CaO﹒6Al2O3B.CaO﹒2Al2O3C.3CaO﹒6Al2O3D.12CaO﹒7Al2O3
A.Al2O3B.AlNC.Al2S3D.AlO