$\,\text{C}{{\text{H}}_{\text{3}}}\text{Br }\xrightarrow{\text{KCN}}A\xrightarrow{{{H}_{3}}O}B\xrightarrow{LiAl{{H}_{4}}}C$
$(I)\,\begin{array}{*{20}{c}}
{C{H_3}CHC{H_2}C{H_3}} \\
{|\,\,\,\,\,\,\,\,\,\,\,} \\
{Cl\,\,\,\,\,\,\,\,\,}
\end{array}$
$(II)\,CH_3CH_2CH_2Cl$
$(III)\,H_3CO-C_6H_4-CH_2Cl$