( ( ( These clouds ) ( in turn ) ) ( ( can ( produce ( ( precipitation , ) ( which ( ( ( ( returns ( the water ) ) back ) ( to ( ( the ( earth 's ) ) surface ) ) ) ( where ( ( the cycle ) ( begins again ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT These) (NNS clouds)) (PP (IN in) (NP (NN turn)))) (VP (MD can) (VP (VB produce) (NP (NP (NN precipitation)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ returns) (NP (DT the) (NN water)) (PRT (RP back)) (PP (TO to) (NP (NP (DT the) (NN earth) (POS 's)) (NN surface))) (SBAR (WHADVP (WRB where)) (S (NP (DT the) (NN cycle)) (VP (VBZ begins) (ADVP (RB again))))))))))) (. .)))
These clouds in turn can produce precipitation, which returns the water back to the earth's surface where the cycle begins again.
(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))))))))))) (. .)))