tabu to textwidth 生成比 textwidth 更宽的表格

Question

我有一个表格代码，它应该适合文本宽度，但不知何故却不适合。有什么想法吗？

\documentclass {article}

\usepackage [T2A] {fontenc}
\usepackage [utf8] {inputenc}
\usepackage [english,russian] {babel}

\usepackage{longtable}
\usepackage{array}
\usepackage{tabu}

\usepackage{lipsum}

\begin{document}

    \lipsum[1-1]
    \tabulinesep = 1mm
    \begin{longtabu} to \textwidth {|c|X[p]|c|c|c|c|c|}
        \hline
        & 
        & \multicolumn{5}{c|}{\bfseries Количество часов} \\ \cline{3-7}
        %
    \bfseries
    \begin{tabular}{c}
        № \\ модуля 
    \end{tabular}
        & \centering\bfseries Наименование модулей
        & \bfseries Всего
        & \multicolumn{3}{c|}{\bfseries%
            \begin{tabular}{c}
            Аудиторная \\ работа 
            \end{tabular}}
        & \bfseries
            \begin{tabular}{c}
            Внеауд. \\ работа \\ СР
            \end{tabular} \\ \cline{4-6}
    &
        &
        & \bfseries Л
        & \bfseries ПЗ
        & \bfseries ЛР
        & 
        \\ \hline
    \end{longtabu}
    \noindent\hrulefill
\end{document}

Answer 1

我不确定为什么（tabu通常有点令人惊讶），但用而不是指定内部tabular环境似乎可以解决问题。@{}c@{}c

\documentclass {article}

\usepackage [T2A] {fontenc}
\usepackage [utf8] {inputenc}
\usepackage [english,russian] {babel}

\usepackage{longtable}
\usepackage{array}
\usepackage{tabu}

\usepackage{lipsum}

\begin{document}

    \lipsum[1-1]
    \tabulinesep = 1mm
    \begin{longtabu} to \textwidth {|c|X[p]|c|c|c|c|c|}
        \hline
        & 
        & \multicolumn{5}{c|}{\bfseries Количество часов} \\ \cline{3-7}
        %
    \bfseries
    \begin{tabular}{@{}c@{}}
        № \\ модуля 
    \end{tabular}
        & \centering\bfseries Наименование модулей
        & \bfseries Всего
        & \multicolumn{3}{c|}{\bfseries%
            \begin{tabular}{@{}c@{}}
            Аудиторная \\ работа 
            \end{tabular}}
        & \bfseries
            \begin{tabular}{@{}c@{}}
            Внеауд. \\ работа \\ СР
            \end{tabular} \\ \cline{4-6}
    &
        &
        & \bfseries Л
        & \bfseries ПЗ
        & \bfseries ЛР
        & 
        \\ \hline
    \end{longtabu}
\end{document}