( Then ( , ( ( the blood ) ( ( is ( ( carried ( to ( the heart ) ) ) ( by ( veins ( and ( lymph vessels ) ) ) ) ) ) . ) ) ) )
(ROOT (S (ADVP (RB Then)) (, ,) (NP (DT the) (NN blood)) (VP (VBZ is) (VP (VBN carried) (PP (TO to) (NP (DT the) (NN heart))) (PP (IN by) (NP (NNS veins) (CC and) (NN lymph) (NNS vessels))))) (. .)))
Then, the blood is carried to the heart by veins and lymph vessels.
(ROOT (S (NP (JJ Lymph) (NNS vessels)) (VP (VBP are) (PP (IN like) (NP (NN blood) (NNS vessels))) (, ,) (SBAR (IN except) (S (NP (PRP they)) (VP (VBP move) (NP (NP (NN lymph)) (PP (RB instead) (IN of) (NP (NN blood)))))))) (. .)))