( ( The ( small intestine ) ) ( ( is ( where ( ( most ( chemical digestion ) ) ( takes place ) ) ) ) . ) )
(ROOT (S (NP (DT The) (JJ small) (NN intestine)) (VP (VBZ is) (SBAR (WHADVP (WRB where)) (S (NP (JJS most) (NN chemical) (NNS digestion)) (VP (VBZ takes) (NP (NN place)))))) (. .)))
The small intestine is where most chemical digestion takes place.
(ROOT (S (NP (NP (JJS Most)) (PP (IN of) (NP (DT the) (NN digestion) (NNS reactions)))) (VP (VBP occur) (PP (IN in) (NP (DT the) (JJ small) (NN intestine)))) (. .)))