\documentclass[12pt]{article} \usepackage{amsmath,multirow} \bigzero{跨行列}{边长} \newcommand{\bigzero}[2]{\multicolumn{#1}{c}{\multirow{#1}*{$\begin{matrix} 0_{#2\times #2} \end{matrix}$}}} \setcounter{MaxMatrixCols}{20} \begin{document} \[\begin{pmatrix} \bi...