\begin{enumerate}
  \item \textbf{Put the sections of the file into separate files, named 
  \texttt{section1.tex}, \texttt{section2.tex}, and \texttt{section3.tex}. 
  Include them using the  \code{\textbackslash include} command.}
  \item \textbf{Which command becomes superfluous when you use 
  \code{\textbackslash include}}
  \item \textbf{Can the preamble also be excluded? If no, why? If yes, why can 
  outsourcing the preamble be useful?}
  \item \textbf{Add the command \code{\textbackslash includeonly\{section2\}} to 
  the 
  preamble. Compile the document again, and check what has changed. What does 
  the command do and why can it be helpful in a larger project? }
\end{enumerate}