A.Na2S2SO3用K2CrO4(K2Cr2O7才是) B.AgNO3用NaCl C.EDTA用ZnO D.NaOH用KHC8H4O4
A.3 B.2 C.1.5 D.4.7
A.17.5安 B.0.0143安 C.0.5安 D.35安