下列实验中,现象及结论都正确,且二者之间有因果关系的是()选项实验操作现象结论A向FeI2溶液中通入少量Cl2溶液变黄Cl2的氧化性强于Fe3+B向NaCl、NaBr的混合稀溶液中滴入少量稀AgNO3溶液有浅黄色沉淀生成Ksp(AgCl) > Ksp(AgBr)C常温下,向NaHS溶液中滴加石蕊试液溶液变蓝Kw>Ka1(H2S)·Ka2(H2S)D向盛有2 mL一定浓度的Na3 [Ag(S2O3)2]溶液的试管中,滴入5滴2 mol· L-1KI溶液产生黄色沉淀[Ag(S2O3)2]3- 能够完全电离 A . A B . B C . C D . D
从所给的四个选项中选择最佳答案
English is used ________ business between countries all
________ the world. [ ]
A.by ... in
B.as ... around
C.for ... over D.with ... on