【簡譜兩條下劃綫可能的畫法】\documentclass[12pt]{article}\usepackage{tikz}\usepackage{amsmath}\begin{document}\newlength{\musiclen}\settowidth{\musiclen}{1155}\noindent\makebox[0pt][l]{1155}%\makebox[0pt][l]{\rule[-0.3ex]{\the\musiclen}{0.4pt}}%\rule[-0.5ex]{\the\musiclen}{0.4pt}\end{document}