( Precipitation ( ( ( returns ( the water ) ) ( to ( ( the ( earth 's ) ) surface ) ) ) . ) )
(ROOT (S (NP (NNP Precipitation)) (VP (VBZ returns) (NP (DT the) (NN water)) (PP (TO to) (NP (NP (DT the) (NN earth) (POS 's)) (NN surface)))) (. .)))
Precipitation returns the water to the earth's surface.
(ROOT (S (NP (NNP Precipitation)) (VP (VBP are) (NP (NP (DT a) (JJ natural) (NN process)) (SBAR (WHNP (WDT that)) (S (VP (VBZ allows) (NP (NN water)) (S (VP (TO to) (VP (VB return) (ADVP (RB again)) (PP (TO to) (NP (NP (DT the) (NN earth) (POS 's)) (NN surface))))))))))) (. .)))