As we all know, music is p___小题1:____ the most importantpart in our day-to-day lives. Some songs can ___小题2:____ (激励) us and drive us forward, while _____小题3:_____ may remind us ___小题4:__ the people whom we love. Many important occasions like those of ___小题5:____ (婚礼) or sports and games have their special music. Every nation has its n____小题6:___ anthem. With years p_____小题7:___ by, music grows and changes.Modern science has also changed music. Inventions like records, radios, movies, ___小题8:____ (电的) instrument, tapes,recorders and videos have changed the way in ___小题9:___ we play and listen to music; they have h___小题10:_____ to make music an important form of international communication.

A、B、C、D四种溶液，它们的阳离子分别是K⁺、Na⁺、Ba²⁺、Fe³⁺，阴离子分别为OH^-、CO₃^2-、NO₃^-、Cl^-（以上8种离子均不重复出现），现进行下列实验：

①A的焰色反应为紫色（透过钴玻璃）．

②B溶液中加入铁粉，溶液质量增加．

③向A、C溶液中分别滴加AgNO₃溶液均产生白色沉淀，再加入稀HNO₃，A中白色沉淀溶解，且有气体生成．

④C中加入稀H₂SO₄时产生白色沉淀．

（1）由上述现象推知各溶液中所含溶质的化学式为：

A．______；B．______；C．______；D．______．

（2）写出C中加H₂SO₄的离子方程式______．

（3）鉴别B中阳离子所用的试剂是______，反应的现象是______．