\documentclass{book}
  \usepackage{lipsum}

\begin{document}

\chapter{Lorem ipsum}

\lipsum[1]

\section{Nam dui ligula}

\lipsum[2-3]

\subsection{Fusce mauris}

\lipsum[4-6]

\end{document}

%%% Local Variables:
%%% mode: latex
%%% TeX-master: t
%%% End:
