bears ... should keep parents amused with its low groan-to-guffaw ratio . 
(ROOT (S (NP (NNS bears)) (, ...) (VP (MD should) (VP (VB keep) (NP (NNS parents)) (S (ADJP (VBN amused))) (PP (IN with) (NP (PRP$ its) (JJ low) (NML (NML (NN groan)) (HYPH -) (PP (IN to) (HYPH -) (NP (NN guffaw)))) (NN ratio))))) (. .)))
(ROOT (S (NP (NNS )) (, ) (VP (MD ) (VP (VB ) (NP (NNS )) (S (ADJP (VBN ))) (PP (IN ) (NP (PRP$ ) (JJ ) (NML (NML (NN )) (HYPH ) (PP (IN ) (HYPH ) (NP (NN )))) (NN ))))) (. )))