$(1)$ $\begin{matrix}
O\,\,\,\,\,\,\,\,\,\,\, \\
||\,\,\,\,\,\,\,\,\,\,\,\, \\
{{H}_{3}}C-C-C{{H}_{2}}-Cl \\
\end{matrix}$
$(2)$ ${{H}_{2}}C-C{{H}_{2}}-C{{H}_{2}}-Cl$
$(3)$ ${{({{H}_{3}}C)}_{3}}C-Cl$
${C{H_3} - C{H_2} - CH = C{H_2} + HBr\,\to \,CH _{3}- CH _{2}- CH _{2}- C^{+}H _{2}+ Br ^{-}} _{"A"}$
${C{H_3} - C{H_2} - CH = C{H_2} + HBr\, \to \,CH _{3}- CH _{2}- C^{+}H - CH _{3}+ Br ^{-}}_{"B"}$