( ( Green plants ) ( ( ( release ( oxygen underwater ) ) ( during photosynthesis ) ) . ) )
(ROOT (S (NP (NNP Green) (NNS plants)) (VP (VBP release) (NP (NN oxygen) (JJ underwater)) (PP (IN during) (NP (NN photosynthesis)))) (. .)))
Green plants release oxygen underwater during photosynthesis.
(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))))) (. .)))