①滴加Mg(NO3)2 溶液 ②过滤 ③滴加AgNO3溶液 ④滴加Ba(NO3)2 溶液.
A:①②④②③
B:④②①②③
C:①②③②④
D:④②③②①
请回答:
— Yes. It is beautiful and has many colours.