错误:
CuSO4 %2B NH4OH %3D H2SO4 %2B %5BCu%28NH3%292%5D%28OH%292
^
不需要的字符 ('%')CuSO4 %2B NH4OH %3D H2SO4 %2B %5BCu%28NH3%292%5D%28OH%292
^
不需要的字符 ('%')