1 $\begin{array}{*{20}{c}}
{{{\rlap{-} [C{H_2} - C = CH - C{H_2}{\mkern 1mu} {\mkern 1mu} \rlap{-} ]}_n}} \\
{|{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} \,\,\,\,\,\,\,\,\,\,\,{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} \,\,\,\,\,\,\,\,\,\,{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} } \\
{Cl{\mkern 1mu} \,\,\,\,\,\,\,\,{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} \,\,\,\,\,\,\,\,\,\,\,{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} }
\end{array}$
2 $\begin{array}{*{20}{c}}
{\,\,\,\,\,\,\,\,Cl} \\
{\,\,\,\,\,|} \\
{\,\,\,\,\,\,\,\,\,\,\,C{H_2}} \\
{\,\,\,\,|} \\
{{{\rlap{-} [\,\,\,C{H_2} - CH - O\,\,\,\rlap{-} ]}_n}}
\end{array}\,$
3 $\begin{array}{*{20}{c}}
{{{\rlap{-} [\,\,\,C{H_3} - C{H_2} - C\,\,\,\rlap{-} ]}_n}} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,||} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,O}
\end{array}$
4