A.PH<1 B.PH1.5~2.5 C.PH5.9 D.PH1.8~2.0
A.40~50℃ B.60~70℃ C.50~70℃ D.70~80℃
A.0.20mol/L B.0.20g/mol C.0.20g/ml D.0.40mol/L