$\begin{array}{*{20}{c}}
{C{H_3}}\\
{|\,\,\,\,\,}\\
{{C_6}{H_5}C{H_2} - C - C{H_2} - C{H_3}}\\
{|\,\,\,\,\,}\\
{Br\,\,\,}
\end{array}$ $\xrightarrow[{{C_2}{H_5}OH}]{{{C_2}{H_5}ONa}}$
$(I)\,\begin{array}{*{20}{c}}
{C{H_3}CHC{H_2}C{H_3}} \\
{|\,\,\,\,\,\,\,\,\,\,\,} \\
{Cl\,\,\,\,\,\,\,\,\,}
\end{array}$
$(II)\,CH_3CH_2CH_2Cl$
$(III)\,H_3CO-C_6H_4-CH_2Cl$