has a monopoly on mindless action 
(ROOT (S (VP (VBZ has) (NP (NP (DT a) (NN monopoly)) (PP (IN on) (NP (JJ mindless) (NN action)))))))
(ROOT (S (VP (VBZ ) (NP (NP (DT ) (NN )) (PP (IN ) (NP (JJ ) (NN )))))))