A:H2SB:SO2C:Cl2D:NO2①A在空气中不完全燃烧:2H2S+O2=2S↓+2H2O②C通入消石灰中:2Cl2+2Ca(OH)2=CaCl2+Ca(ClO)2+2H2O③D通入水中:3NO2+H2O=2HNO3+NO④A通入硫酸铜溶液:S^2- + Cu = CuS↓⑤B通入NaOH溶液: SO2+2OH^- = SO3^2- + H2O⑥C通入水中:Cl2 + H2O = HClO + H^+ + Cl^-