a tart , smart breath of fresh air 
(ROOT (NP (NP (DT a) (NN tart) (, ,) (JJ smart) (NN breath)) (PP (IN of) (NP (JJ fresh) (NN air)))))
(ROOT (NP (NP (DT ) (NN ) (, ) (JJ ) (NN )) (PP (IN ) (NP (JJ ) (NN )))))