( ( ( high concentration ) ( of ( urea 2 ) ) ) . )
(ROOT (NP (NP (JJ high) (NN concentration)) (PP (IN of) (NP (NN urea) (CD 2))) (. .)))
high concentration of urea 2.
(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)))))) (. .)))