( ( FOOD ( CHAINS Animals ) ) ( ( must ( ( ( eat food ) , ) ( since ( they ( ( can not ) ( ( produce it ) themselves ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP FOOD) (NNP CHAINS) (NNPS Animals)) (VP (MD must) (VP (VB eat) (NP (NN food)) (, ,) (SBAR (IN since) (S (NP (PRP they)) (VP (MD can) (RB not) (VP (VB produce) (NP (PRP it)) (NP (PRP themselves)))))))) (. .)))
FOOD CHAINS Animals must eat food, since they can not produce it themselves.
(ROOT (S (NP (NP (DT A) (NN consumer) (CC and) (NN producer)) (PP (IN in) (NP (DT a) (NN food) (NN chain)))) (VP (VBP are) (VP (VBN involved) (SBAR (WHADVP (WRB when)) (S (NP (DT a) (NNS deer)) (VP (VBZ eats) (NP (DT a) (NN leaf))))))) (. .)))