$(1)$ $\begin{matrix} O\,\,\,\,\,\,\,\,\,\,\, \\ ||\,\,\,\,\,\,\,\,\,\,\,\, \\ {{H}_{3}}C-C-C{{H}_{2}}-Cl \\ \end{matrix}$
$(2)$ ${{H}_{2}}C-C{{H}_{2}}-C{{H}_{2}}-Cl$
$(3)$ ${{({{H}_{3}}C)}_{3}}C-Cl$