错误:
H3O%3A%2B %2B NO2%3A- %2B MnO4%3A- %3D NO3%3A- %2B Mn%3A2%2B %2B H2O
^
不需要的字符 ('%')H3O%3A%2B %2B NO2%3A- %2B MnO4%3A- %3D NO3%3A- %2B Mn%3A2%2B %2B H2O
^
不需要的字符 ('%')