A:硫化亚铁溶于稀硝酸中:FeS+2H+=Fe2++H2S↑
B:NH4HCO3溶于过量的NaOH溶液中:HCO3﹣+OH﹣=CO32﹣+H2O
C:少量SO2通入苯酚钠溶液中:C6H5O﹣+SO2+H2O=C6H5OH+HSO3﹣
D:大理石溶于醋酸中:CaCO3+2CH3COOH=Ca2++2CH3COO﹣+CO2↑+H2O
Say “I’m sorry.” When you a mistake.
如图,a∥b,∠1=40°,∠2=80°,则∠3=____ 度.