( Herbivores ( ( are ( ( those animals ) ( which ( eat ( only plants ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Herbivores)) (VP (VBP are) (NP (NP (DT those) (NNS animals)) (SBAR (WHNP (WDT which)) (S (VP (VBP eat) (NP (JJ only) (NNS plants))))))) (. .)))
Herbivores are those animals which eat only plants.
(ROOT (S (NP (NNS Herbivores)) (VP (VBP are) (NP (NP (NNS heterotrophs)) (SBAR (WHNP (WDT that)) (S (VP (VBP eat) (NP (UCP (ADJP (JJ only)) (CC or) (ADVP (RB mainly))) (NNS plants))))))) (. .)))