测试文章
$W_\mathrm{静}=\frac12mv_2^2-\frac12mv_1^2$
$$ \Delta E_k=\frac12mv^2 \\ \begin{array}{c|lcr} n & \text{Left} & \text{Center} & \text{Right} \\ \hline 1 & 0.24 & 1 & 125 \\ 2 & -1 & 189 & -8 \\ 3 & -20 & 2000 & 1+10i \end{array} $$
$$ \begin{align} x &= 2 \\ y &= 3 \\ z &= x + y \end{align} $$
