Give the resonance structures of nitromethane and explain its real structure.

(N/A) Nitromethane $(CH_{3}NO_{2})$ can be represented by two Lewis structures,$(I)$ and $(II)$,which are its resonance structures as shown below:
$H_{3}C-N^{+}(=O)-O^{-} \longleftrightarrow H_{3}C-N^{+}(O^{-})=O$
In these individual Lewis structures,there appear to be two different types of $N-O$ bonds: one single bond and one double bond.
However,experimental evidence shows that both $N-O$ bonds in nitromethane have the same bond length,which is intermediate between a $N-O$ single bond and a $N=O$ double bond.
Therefore,the actual structure of nitromethane is a resonance hybrid of the two canonical forms $(I)$ and $(II)$.