( ( ( ( ( The ( small intestine ) ) , ) ( where ( ( most digestion ) ( takes place ) ) ) ) , ) ( ( is ( ( a ( convoluted tube ) ) ( in ( ( the abdomen ) ( that ( ( ( begins ( at ( ( the pylorus ) ( of ( the stomach ) ) ) ) ) and ) ( ( ends ( at ( the opening ) ) ) ( to ( the ( large intestine ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ small) (NN intestine)) (, ,) (SBAR (WHADVP (WRB where)) (S (NP (JJS most) (NNS digestion)) (VP (VBZ takes) (NP (NN place))))) (, ,)) (VP (VBZ is) (NP (NP (DT a) (ADJP (JJ convoluted)) (NN tube)) (PP (IN in) (NP (NP (DT the) (NN abdomen)) (SBAR (WHNP (WDT that)) (S (VP (VP (VBZ begins) (PP (IN at) (NP (NP (DT the) (NNS pylorus)) (PP (IN of) (NP (DT the) (NN stomach)))))) (CC and) (VP (VBZ ends) (PP (IN at) (NP (DT the) (NN opening))) (PP (TO to) (NP (DT the) (JJ large) (NN intestine))))))))))) (. .)))
The small intestine, where most digestion takes place, is a convoluted tube in the abdomen that begins at the pylorus of the stomach and ends at the opening to the large 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)))) (. .)))