( They ( ( host ( ( intestinal parasites ) ( such ( as ( ( hookworms and ) tapeworms ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VB host) (NP (NP (JJ intestinal) (NNS parasites)) (PP (JJ such) (IN as) (NP (NNS hookworms) (CC and) (NNS tapeworms))))) (. .)))
They host intestinal parasites such as hookworms and tapeworms.
(ROOT (S (NP (DT A) (NN hookworm)) (VP (VBZ is) (VP (VBN classified) (PP (IN as) (NP (DT a) (NN parasite))))) (. .)))
A hookworm is classified as a parasite.