Đáp án đúng: A khí CO2 $\text{AlO}_{\text{2}}^{\text{-}}\,\text{+}\,\text{C}{{\text{O}}_{\text{2}}}\,\text{+}\,\text{2}{{\text{H}}_{\text{2}}}\text{O}\,\xrightarrow{{}}\,\text{Al(OH}{{\text{)}}_{\text{3}}}\downarrow \,\text{+}\,\text{HCO}_{\text{3}}^{\text{-}}$