Which of the following can not react with Bayer's reagent?

Which of the following compounds has two different $C-C$ bond lengths?

Given the following structures:
$(I)$ $1,3,5-$trimethylbenzene (mesitylene)
$(II)$ $1,3-$dimethyl$-5-$methylenecyclohexa$-1,3-$diene
$(III)$ $1,3,5-$trimethylenecyclohexane
The enthalpy of hydrogenation of these compounds will be in the order as:

In the $Friedel-Crafts$ reaction,anhydrous $AlCl_3$ is used because it is ............

For the electrophilic aromatic substitution reaction on the benzene ring,the substituents are $-CH_3$,$-CH_2Cl$,$-CHCl_2$,and $-CCl_3$. What is the increasing order of reactivity towards electrophilic substitution?

Which of the following groups possess $m-$directional effect?
$-OH, -O^{-}, -CH_3, -Cl, -NO_2, -COOH, -NHCOCH_3, -SO_3H, -Br, -COCH_3$