1 $\begin{array}{*{20}{c}}
{C{H_2}OH - C{H_2} - C{H_2} - CH - C{H_2}OH} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|}\,\,\,\,\,\, \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,OH}
\end{array}$ and (image)
2 (image) and $\begin{array}{*{20}{c}}
{C{H_2}OH - C{H_2} - C{H_2} - CH - C{H_2}OH} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,OH}
\end{array}$
3 Both are
4 Both are $\begin{array}{*{20}{c}}
{C{H_2}OH - C{H_2} - C{H_2} - CH - C{H_2}OH} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,OH}
\end{array}$