b c {\displaystyle {\frac {b}{c}}} Brian楊[1]是一個大帥哥
\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}-}}}}