( ( Its toxicity ) ( ( is ( very low ) ) . ) )
(ROOT (S (NP (PRP$ Its) (NN toxicity)) (VP (VBZ is) (ADJP (RB very) (JJ low))) (. .)))
Its toxicity is very low.
(ROOT (S (NP (NP (DT The) (JJ main) (NN advantage)) (PP (IN of) (NP (NN urea)))) (VP (VBZ is) (NP (PRP$ its) (ADJP (RB very) (JJ low)) (NN toxicity))) (. .)))