\documentclass[12pt,twoside]{ctexbook}
\usepackage{array}
\usepackage{zhlipsum}
\usepackage{color}
\usepackage{enumitem}
\setlist[trivlist, 1]{topsep=0pt,partopsep=0pt,parsep=0pt}
\begin{document}
\zhlipsum[1]
\begin{center}
\begin{tabular}{p{0.9\textwidth}}
\hline
\textcolor{red}{这里center环境会和上下文有一定的额外间距,不知该如何减小或消除。尝试过用enumitem宏包,设置trivlist,并未成功}\\
\hline
\end{tabular}
\end{center}
\zhlipsum[1]
\end{document}
问 如何减小或消除center环境会和上下文的额外间距