错误:
CuSO4 %2B NH4OH %3D %28NH4%292SO4 %2B Cu2%28OH%292SO4
^
不需要的字符 ('%')CuSO4 %2B NH4OH %3D %28NH4%292SO4 %2B Cu2%28OH%292SO4
^
不需要的字符 ('%')