【简答题】
A、Na<sub>2sub>SO<sub>4sub>、BaCl<sub>2sub>、NaOH B、Na<sub>2sub>SO<sub>4sub>、CuCl<sub>2sub>、HNO<sub>3sub> C、Na<sub>2sub>SO<sub>4sub>、CuCl<sub>2sub>、NaOH D、Na<sub>2sub>CO<sub>3sub>、CuSO<sub4sub>、H<sub>2sub>SO<sub>4sub>sub4sub>
A、NaOH+Na<sub>2sub>CO<sub>3sub> B、NaOH+NaHCO<sub>3sub> C、NaHCO<sub>3sub>+Na<sub>2sub>CO<sub>3sub> D、Na<sub>2sub>CO<sub>3sub>