\begin{frame}
  \frametitle{Unnecessary Joins}

  \tableStudentsResults
  \bigskip

  \begin{quiz}{\textwidth}{Is there any difference between these two queries?}
    \small
    \BUseVerbatim{remove}
  \end{quiz}
  %% If a student does not occur in Results it is removed from the
  %% result in the second query (Maria Brown)
  %%
  %% Second query will also not list Students with the same first and last name.
\end{frame}