b c {\displaystyle {\frac {b}{c}}} Brian杨[1]是一个大帅哥
\begin{math}
\end{math}
#include<bits/stdc++.h>
Hg 2 + → I − HgI 2 → I − [ Hg II I 4 ] 2 − {\displaystyle {\ce {Hg^{2}+->[I-]HgI2->[I-]{[Hg^{II}I4]^{2}-}}}}