\usepackage{subfig}


\begin{figure}[h]%
        \centering
        \subfloat[lr=10]{{\includegraphics[scale=.33]{part1/training_normalized_lr=10_part_1.png} }}%
        \hfill
        \subfloat[lr=1]{{\includegraphics[scale=.33]{part1/training_normalized_lr=1_part_1.png} }}%

        \subfloat[lr=10]{{\includegraphics[scale=.33]{part1/training_normalized_lr=10_part_1.png} }}%
        \hfill
        \subfloat[lr=1]{{\includegraphics[scale=.33]{part1/training_normalized_lr=1_part_1.png} }}%
\end{figure}