( ( In ( combination reactions ) ) ( , ( ( ( ( two or ) more ) compounds ) ( ( react ( to ( form ( one product ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (NN combination) (NNS reactions))) (, ,) (NP (QP (CD two) (CC or) (JJR more)) (NNS compounds)) (VP (VBP react) (S (VP (TO to) (VP (VB form) (NP (CD one) (NN product)))))) (. .)))
In combination reactions, two or more compounds react to form one product.
(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)))))))))) (. .)))