H2S04質(zhì)量分?jǐn)?shù)控制在()時酸的活性最強,即酸洗時間最短。
A.15% B.25% C.35% D.45%
A.40~50 B.50~60 C.60~70 D.70~80
A.350 B.400 C.450 D.335