( ( The ( tissue cells ) ) ( ( ( ( ( use oxygen ) ( in ( their ( energy reactions ) ) ) ) , ) ( ( ( producing ( carbon dioxide ) ) & ) ( water ( as ( a result ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN tissue) (NNS cells)) (VP (VBP use) (NP (NN oxygen)) (PP (IN in) (NP (PRP$ their) (NN energy) (NNS reactions))) (, ,) (NP (NP (VBG producing) (NN carbon) (NN dioxide)) (CC &) (NP (NP (NN water)) (PP (IN as) (NP (DT a) (NN result)))))) (. .)))
The tissue cells use oxygen in their energy reactions, producing carbon dioxide & water as a result.
(ROOT (S (NP (NNP Combustion) (NNS reactions)) (VP (VBP involve) (S (NP (NP (DT the) (NN reaction)) (PP (IN of) (NP (NP (DT a) (NN hydrocarbon)) (PP (IN with) (NP (NN oxygen) (NN gas)))))) (VP (TO to) (VP (VB produce) (NP (NN water) (CC and) (NN carbon) (NN dioxide)))))) (. .)))