( ( ( ( ( ( At ( ( high humidity ) ( of air ) ) ) ( evaporation ( is ( slowed down ) ) ) ) , ) and ) ( ( ( the requirement ) ( of ( ( a plant ) ( for water ) ) ) ) decreases ) ) . )
(ROOT (S (S (PP (IN At) (NP (NP (JJ high) (NN humidity)) (PP (IN of) (NP (NN air))))) (NP (NN evaporation)) (VP (VBZ is) (VP (VBN slowed) (PRT (RP down))))) (, ,) (CC and) (S (NP (NP (DT the) (NN requirement)) (PP (IN of) (NP (NP (DT a) (NN plant)) (PP (IN for) (NP (NN water)))))) (VP (VBZ decreases))) (. .)))
At high humidity of air evaporation is slowed down, and the requirement of a plant for water decreases.
(ROOT (S (NP (NNP Humidity) (NNP happens)) (VP (VBZ happens) (SBAR (WHADVP (WRB when)) (S (NP (JJ liquid) (NN water)) (VP (VBZ evaporates))))) (. .)))