$(i)$ $\begin{array}{*{20}{c}}
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,C{H_3}} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|} \\
{C{H_3} - {C^ \mathbf{-} }} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,C{H_3}}
\end{array}$
$(ii)\;\;CH_2 = CH -\stackrel{\mathbf{-}}{C}H_2$
$(iii)\;\;CH \equiv \stackrel{\mathbf{-}}{C}$
$(iv)\;\;\stackrel{\mathbf{-}}{C}H_3$
$(v)\;\;\stackrel{\mathbf{-}}{C}N$
$(a)\,\,CH_3CO_2^-$ $(b)\,\,H_2O$
$(c)\,\,CH_3SO_3^-$ $(d)\,\,\bar OH$
$\underset{A}{\mathop{PhF}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\underset{B}{\mathop{PhCl}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\underset{C}{\mathop{PhBr}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\underset{D}{\mathop{PhI}}\,$