1 \(CH_3CH_2 - OH\)
2 $\begin{array}{*{20}{c}}
{C{H_3} - CH - C{H_2} - C{H_{3\,\,\,\,}}} \\
{\,\,\,\,|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{OH\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}
\end{array}\,\,$
3 $\begin{array}{*{20}{c}}
{\,\,\,\,\,\,\,\,C{H_3}} \\
\,\,| \\
{C{H_3} - C - OH} \\
\,\, | \\
{\,\,\,\,\,\,\,\,C{H_3}}
\end{array}$
4 \(CH_3-OH\)