( Sharks ( ( maintain ( ( high concentrations ) ( of urea ) ) ) . ) )
(ROOT (S (NP (NNS Sharks)) (VP (VBP maintain) (NP (NP (JJ high) (NNS concentrations)) (PP (IN of) (NP (NN urea))))) (. .)))
Sharks maintain high concentrations of urea.
(ROOT (S (NP (NNS Animals)) (VP (MD can) (VP (VP (VB transport) (NP (NP (DT the) (NN waste) (NN material)) (VP (VBN known) (PP (IN as) (NP (NP (NN urea)) (PP (IN in) (NP (DT the) (JJ circulatory) (NN system)))))))) (CC and) (VP (VB store) (NP (PRP it)) (ADVP (RB safely)) (PP (IN at) (NP (JJ high) (NNS concentrations)))))) (. .)))