( ( Their bodies ) ( ( were ( pricked ( by ( cactus spines ) ) ) ) . ) )
(ROOT (S (NP (PRP$ Their) (NNS bodies)) (VP (VBD were) (VP (VBN pricked) (PP (IN by) (NP (NN cactus) (NNS spines))))) (. .)))
Their bodies were pricked by cactus spines.
(ROOT (S (NP (NP (DT The) (NNS spines)) (PP (IN of) (NP (DT a) (NN cactus)))) (VP (VBP help) (SBAR (S (NP (PRP it)) (VP (VBP survive) (SBAR (IN because) (S (NP (NNS spines)) (VP (VB protect) (NP (DT the) (NN cactus)) (PP (IN from) (NP (NNS animals)))))))))) (. .)))