( ( reverse ( ( ( photosynthesis ( -LRB- ( ( ( ( ( plants ( also ( begin ( to ( use oxygen ) ) ) ) ) , ) as ) ( the ( sun-light decreases ) ) ) -RRB- ) ) ) and ) ( ( many ( other ( interesting areas ) ) ) ( of study ) ) ) ) . )
(ROOT (S (VP (VB reverse) (NP (NP (NP (NN photosynthesis)) (PRN (-LRB- -LRB-) (NP (NP (NP (NNS plants)) (VP (ADVP (RB also)) (VBP begin) (S (VP (TO to) (VP (VB use) (NP (NN oxygen))))))) (, ,) (RB as) (NP (DT the) (JJ sun-light) (NNS decreases))) (-RRB- -RRB-))) (CC and) (NP (NP (JJ many) (JJ other) (JJ interesting) (NNS areas)) (PP (IN of) (NP (NN study)))))) (. .)))
reverse photosynthesis (plants also begin to use oxygen, as the sun-light decreases) and many other interesting areas of study.
(ROOT (S (NP (NNP Oxygen)) (VP (VBZ is) (VP (VBN made) (PP (IN by) (NP (NP (NNS trees)) (CC and) (NP (JJ other) (NNS plants)))) (PP (IN during) (NP (NN photosynthesis))))) (. .)))