Statement 1: Withdrawing group present only at ortho & para position shows effect but not at meta position on nucleophilic substitution of chloro benzene

Statement 2: Carbanion formed is stabilizes through resonance by the presence of $-{\mathrm{NO}}_2$ gp ortho & para but not when present at meta position 

Intermediate is carbanion, negative charge delocalized at ortho & para position. 

$\therefore$ carbanion is stabilized by EWG $\left(-{\mathrm{NO}}_2,-\mathrm{CHO}....\mathrm{etc}\right)$

Carbanion is destabilized by EDG $\left(-{\mathrm{OCH}}_3,-{\mathrm{CH}}_3\right)$

Greater the number of  $-N{O}_2$ groups at ortho & para position more will be the rate of reactivity towards nucleophilic substitution

$-{\mathrm{NO}}_2$ gp at meta position has negligible effect. In fact, reactivity of nucleophilic substitution