( ( The gills ) ( ( open ( through ( ( the pharynx ) ( to ( the outside ) ) ) ) ) ... ) )
(ROOT (S (NP (DT The) (NNS gills)) (ADJP (JJ open)) (PP (IN through) (NP (NP (DT the) (NN pharynx)) (PP (TO to) (NP (DT the) (NN outside))))) (: ...)))
The gills open through the pharynx to the outside...
(ROOT (S (NP (NNP Jaws) (CC and) (NN pharynx) (NNS muscles)) (VP (VBP are) (VP (VBN used) (S (VP (TO to) (VP (VB pump) (NP (NN water)) (PP (IN over) (NP (DT the) (NNS gills)))))))) (. .)))