A、H<sub>2sub>SO<sub>4sub>Na<sub>2sub>CO<sub>3sub>BaCl<sub>2sub>HCl B、HClH<sub>2sub>SO<sub>4sub>Na<sub>2sub>CO<sub>3sub>BaCl<sub>2sub> C、Na<sub>2sub>CO<sub>3sub>H<sub>2sub>SO<sub>4sub>HClBaCl<sub>2sub> D、BaCl<sub>2sub>HClNa<sub>2sub>CO<sub>3sub>H<sub>2sub>SO<sub>4sub>