piss on trees , b.s. one another 
(ROOT (NP (VP (VB piss) (PP (IN on) (NP (NNS trees)))) (, ,) (NP (NP (NN b.s.)) (NP (CD one) (DT another)))))
(ROOT (NP (VP (VB ) (PP (IN ) (NP (NNS )))) (, ) (NP (NP (NN )) (NP (CD ) (DT )))))