( ( The spines ) ( ( are ( ( removed , ) ( then ( driven ( into ( ( the cactus ) ( like nails ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS spines)) (VP (VBP are) (VP (VP (VBN removed)) (, ,) (VP (ADVP (RB then)) (VBN driven) (PP (IN into) (NP (NP (DT the) (NN cactus)) (PP (IN like) (NP (NNS nails)))))))) (. .)))
The spines are removed, then driven into the cactus like nails.
(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)))))))))) (. .)))