( ( ( ( ( ( ( A reaction ) ( involving ( ( a substance ) ( that ( produces ( ( two ( different forms ) ) ( of ( the substance ) ) ) ) ) ) ) ) , ) ( one ( more oxidized ) ) ) and ) ( ( the other ) ( more ( reduced ( than ( the original ) ) ) ) ) ) . )
(ROOT (S (S (NP (DT A) (NN reaction)) (VP (VBG involving) (NP (NP (DT a) (NN substance)) (SBAR (WHNP (WDT that)) (S (VP (VBZ produces) (NP (NP (CD two) (JJ different) (NNS forms)) (PP (IN of) (NP (DT the) (NN substance)))))))))) (, ,) (S (NP (PRP one)) (ADJP (RBR more) (JJ oxidized))) (CC and) (S (NP (DT the) (JJ other)) (ADJP (RBR more) (JJ reduced) (PP (IN than) (NP (DT the) (JJ original))))) (. .)))
A reaction involving a substance that produces two different forms of the substance, one more oxidized and the other more reduced than the original.
(ROOT (S (NP (DT A) (NN combination) (NN reaction)) (VP (VBZ is) (NP (NP (DT a) (NN reaction)) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (NP (CD two) (CC or) (JJR more) (NNS substances)) (VP (VBP combine) (S (VP (TO to) (VP (VB form) (NP (DT a) (JJ single) (JJ new) (NN substance)))))))))) (. .)))