单项选择题
A.20B.25C.30D.40
A.3:2B.4:3C.5:4D.4:4
A.1:2B.2:3C.2:1D.3:3
A.0.45B.0.5C.1D.0.15
A.1B.2C.3D.4
A.0.01B.0.02C.0.03D.0.04
A.非晶形沉淀B.胶状沉淀C.晶形沉淀D.颗粒沉淀
A.EDTAB.碱C.还原剂D.氧化剂
A.1420B.1535C.1560D.1750
A.升高B.降低C.不影响
A.5B.15C.10D.20