( ( Most ( of ( ( digestion and ) absorption ) ) ) ( ( occur ( in ( the ( small intestine ) ) ) ) . ) )
(ROOT (S (NP (NP (JJS Most)) (PP (IN of) (NP (NN digestion) (CC and) (NN absorption)))) (VP (VBP occur) (PP (IN in) (NP (DT the) (JJ small) (NN intestine)))) (. .)))
Most of digestion and absorption occur in the small intestine.
(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)))) (. .)))