( ( Intestinal hookworms ) ( ( are ( parasites ( of ( grazing ( ( livestock and ) man ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Intestinal) (NNS hookworms)) (VP (VBP are) (NP (NP (NNS parasites)) (PP (IN of) (NP (NN grazing) (NN livestock) (CC and) (NN man))))) (. .)))
Intestinal hookworms are parasites of grazing livestock and man.
(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.