sustain a reasonable degree of suspense 
(ROOT (S (VP (VB sustain) (NP (NP (DT a) (JJ reasonable) (NN degree)) (PP (IN of) (NP (NN suspense)))))))
(ROOT (S (VP (VB ) (NP (NP (DT ) (JJ ) (NN )) (PP (IN ) (NP (NN )))))))