( ( Leather chaps ) ( ( ( were often ) ( worn ( to ( ( ( ( protect ( ( the ( cowboy 's ) ) legs ) ) ( from ( cactus spines ) ) ) and ) ( ( prevent ( the fabric ) ) ( from ( wearing out ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Leather) (NNS chaps)) (VP (VBD were) (ADVP (RB often)) (VP (VBN worn) (S (VP (TO to) (VP (VP (VB protect) (NP (NP (DT the) (NN cowboy) (POS 's)) (NNS legs)) (PP (IN from) (NP (NN cactus) (NNS spines)))) (CC and) (VP (VB prevent) (NP (DT the) (NN fabric)) (PP (IN from) (S (VP (VBG wearing) (PRT (RP out))))))))))) (. .)))
Leather chaps were often worn to protect the cowboy's legs from cactus spines and prevent the fabric from wearing out.
(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)))))))))) (. .)))