has enough laughs to sustain interest to the end 
(ROOT (S (VP (VBZ has) (NP (JJ enough) (NNS laughs) (S (VP (TO to) (VP (VB sustain) (NP (NN interest)) (PP (IN to) (NP (DT the) (NN end))))))))))
(ROOT (S (VP (VBZ ) (NP (JJ ) (NNS ) (S (VP (TO ) (VP (VB ) (NP (NN )) (PP (IN ) (NP (DT ) (NN ))))))))))