\begin{frame} \frametitle{Exam Task from 2005} \vspace{-1.5ex} \begin{center} \includegraphics[width=.78\textwidth,trim=0mm 10mm 0mm 30mm,clip]{../derivatives/picture_exam2003.pdf}\\ \quad\quad\quad\quad\includegraphics[width=.78\textwidth]{../derivatives/picture_exam2003b.pdf} \pause\quad \raisebox{2cm}{C} \end{center} \end{frame}