( ( ( The ( actual cause ) ) ( of ( the seasons ) ) ) ( ( is ( ( ( the 23 ) - ) ( ( degree tilt ) ( of ( ( the ( Earth 's ) ) axis ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ actual) (NN cause)) (PP (IN of) (NP (DT the) (NNS seasons)))) (VP (VBZ is) (NP (NP (DT the) (CD 23)) (: -) (NP (NP (NN degree) (NN tilt)) (PP (IN of) (NP (NP (DT the) (NN Earth) (POS 's)) (NNS axis)))))) (. .)))
The actual cause of the seasons is the 23 -degree tilt of the Earth's axis.
(ROOT (S (NP (NP (DT The) (NN tilt)) (PP (IN of) (NP (NP (NN earth)) (PP (IN on) (NP (PRP$ its) (NNS axis)))))) (VP (VBZ is) (NP (NP (CD one) (NN factor)) (SBAR (WHNP (WDT that)) (S (VP (VBZ contributes) (PP (TO to) (NP (NP (NNS seasons)) (VP (VBG occurring) (PP (IN in) (NP (JJ new) (NN york) (NN state))))))))))) (. .)))