A.鎂碳材質(zhì)B.鋁碳材質(zhì)C.鋁鎂材質(zhì)D.粘土材質(zhì)
A.鋼包左右不對(duì)準(zhǔn)鐵水包B.鋼包前后不對(duì)準(zhǔn)鐵水包C.鋼包高度太高D.包口結(jié)渣
A.θ<30B.θ=30~60C.θ=60~90D.θ>30