( ( Carbohydrates Carbohydrates ) ( ( are ( substances ( ( whose molecules ) ( contain ( ( ( ( ( ( the ( elements carbon ) ) , ) hydrogen ) , ) and ) ( oxygen ( ( in which ) ( ( ( the ratio ) ( of ( hydrogen ( to oxygen ) ) ) ) ( is ( ( 2 to ) 1 ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Carbohydrates) (NNP Carbohydrates)) (VP (VBP are) (NP (NP (NNS substances)) (SBAR (WHNP (WP$ whose) (NNS molecules)) (S (VP (VBP contain) (NP (NP (DT the) (NNS elements) (NN carbon)) (, ,) (NP (NN hydrogen)) (, ,) (CC and) (NP (NP (NN oxygen)) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (NP (NP (DT the) (NN ratio)) (PP (IN of) (NP (NP (NN hydrogen)) (PP (TO to) (NP (NN oxygen)))))) (VP (VBZ is) (NP (QP (CD 2) (TO to) (CD 1))))))))))))) (. .)))
Carbohydrates Carbohydrates are substances whose molecules contain the elements carbon, hydrogen,  and oxygen in which the ratio of hydrogen to oxygen is 2 to 1.
(ROOT (S (NP (NNP Carbohydrate)) (VP (VBZ contains) (NP (NN carbon) (, ,) (NN hydrogen) (, ,) (CC and) (NN oxygen)) (PP (IN in) (NP (NP (DT a) (NN ratio)) (PP (IN of) (NP (CD 1:2:1)))))) (. .)))