( Circulatory ( System - ) )
(ROOT (NP (NNP Circulatory) (NNP System) (: -)))
Circulatory System -
(ROOT (S (NP (NNS Echinoderms)) (VP (VBP possess) (NP (DT a) (JJ water-based) (NN circulatory) (NN system))) (. .)))