( ( A person ) ( ( can ( ( ( survive ( ( about two ) months ) ) ( without ( ( ( food , ) ( but only ) ) ( a ( few days ) ) ) ) ) ( without water ) ) ) . ) )
(ROOT (S (NP (DT A) (NN person)) (VP (MD can) (VP (VB survive) (NP (QP (RB about) (CD two)) (NNS months)) (PP (IN without) (NP (NP (NN food)) (, ,) (CONJP (CC but) (RB only)) (NP (DT a) (JJ few) (NNS days)))) (PP (IN without) (NP (NN water))))) (. .)))
A person can survive about two months without food, but only a few days without water.
(ROOT (S (NP (JJS Most) (NNS people)) (VP (MD can) (VP (VB survive) (NP (QP (RB only) (DT a) (JJ few)) (NNS days)) (PP (IN without) (NP (NN water))))) (. .)))