Write down the products of ozonolysis of $1,2-$dimethylbenzene ($o-$xylene). How does the result support the Kekul\text{é} structure for benzene?

(N/A) The ozonolysis of $o-$xylene ($1,2-$dimethylbenzene) yields three products: methylglyoxal $(CH_3COCHO)$,$1,2-$dimethylglyoxal $(CH_3COCOCH_3)$,and glyoxal $(CHOCHO)$.
Structure $(I)$ on ozonolysis gives $2$ moles of methylglyoxal and $1$ mole of glyoxal.
Structure $(II)$ on ozonolysis gives $1$ mole of $1,2-$dimethylglyoxal and $2$ moles of glyoxal.
Since all three products are obtained experimentally,it confirms that $o-$xylene exists as a resonance hybrid of the two Kekul\text{é} structures ($I$ and $II$).