A.連鑄凈環(huán)B.連鑄濁環(huán)C.轉(zhuǎn)爐濁環(huán)D.轉(zhuǎn)爐凈環(huán)
A.≤100mg/LB.≤50mg/LC.≤20mg/LD.≤10mg/L
A.1小時(shí)B.2小時(shí)C.3小時(shí)D.4小時(shí)