one ca n't deny its seriousness and quality . 
(ROOT (S (NP (PRP one)) (VP (MD ca) (RB n't) (VP (VB deny) (NP (PRP$ its) (NN seriousness) (CC and) (NN quality)))) (. .)))
(ROOT (S (NP (PRP )) (VP (MD ) (RB ) (VP (VB ) (NP (PRP$ ) (NN ) (CC ) (NN )))) (. )))