( Evaporation ( ( is ( when ( ( the sun ) ( ( ( ( heats up ) ( water ( in ( ( ( ( rivers or ) lakes ) or ) ( the ocean ) ) ) ) ) and ) ( ( turns it ) ( into ( ( vapor or ) steam ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Evaporation)) (VP (VBZ is) (SBAR (WHADVP (WRB when)) (S (NP (DT the) (NN sun)) (VP (VP (VBZ heats) (PRT (RP up)) (NP (NP (NN water)) (PP (IN in) (NP (NP (NNS rivers) (CC or) (NNS lakes)) (CC or) (NP (DT the) (NN ocean)))))) (CC and) (VP (VBZ turns) (NP (PRP it)) (PP (IN into) (NP (NN vapor) (CC or) (NN steam)))))))) (. .)))
Evaporation is when the sun heats up water in rivers or lakes or the ocean and turns it into vapor or steam.
(ROOT (S (NP (NP (NNP Heat)) (PP (IN from) (NP (DT the) (NN sun)))) (VP (VBZ causes) (NP (NP (DT the) (JJS most) (NN evaporation)) (PP (IN of) (NP (NN water)))) (PP (IN from) (NP (DT a) (NN lake)))) (. .)))
Heat from the sun causes the most evaporation of water from a lake.