( Plants ( ( ( ( ( give off ) oxygen ) and ) ( take ( in ( carbon dioxide ) ) ) ) . ) )
(ROOT (S (NP (NNS Plants)) (VP (VP (VB give) (PRT (RP off)) (NP (NN oxygen))) (CC and) (VP (VB take) (PP (IN in) (NP (NN carbon) (NN dioxide))))) (. .)))
Plants give off oxygen and take in carbon dioxide.
(ROOT (S (NP (NN Oxygen) (NN gas)) (VP (VBZ is) (VP (VBN given) (PRT (RP off)) (PP (IN by) (NP (NNS plants))))) (. .)))