（16分）物质在水中可能存在电离平衡、盐的水解平衡等，它们都可看作化学平衡。请根据所学的知识回答：

(1)0.01mol/L的NH₄Cl溶液中各种离子的浓度由大到小顺序为                         ;电荷守恒关系：                                        ；浓度为0.01mol/L的是          ；          和           两种粒子的浓度之和是0.01mol/L。

(2 )CH₃COONa溶液中存在的2个平衡体系分别为(分别用离子方程式表示)：                                  、                                    ；

(3) FeCl₃溶液与Na₂CO₃溶液混合后，反应的离子方程式为                                .

_______, there would be no air around the earth.

A．There were no gravity

B．There was not any gravity

C．Were there no gravity

D．was there no gravity