$(i)$ $\begin{array}{*{20}{c}}
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,C{H_3}} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|} \\
{C{H_3} - {C^ \mathbf{-} }} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,C{H_3}}
\end{array}$
$(ii)\;\;CH_2 = CH -\stackrel{\mathbf{-}}{C}H_2$
$(iii)\;\;CH \equiv \stackrel{\mathbf{-}}{C}$
$(iv)\;\;\stackrel{\mathbf{-}}{C}H_3$
$(v)\;\;\stackrel{\mathbf{-}}{C}N$
$1.\,\,(CH_3)_2 - \mathop C\limits^ + - CH_2 - CH_3$
$2.\,\,(CH_3)_3 - \mathop C\limits^ + $
$3.\,\,(CH_3)_2 - |\mathop C\limits^ + H|$
$4.\,\,CH_3 - \mathop C\limits^ + H_2$
$5.\,\,\mathop C\limits^ + H_3$