Crustaceans are herbivores, carnivores, or scavengers and are often vital elements of the food chain.
(Crustaceans; are; herbivores, carnivores, or scavengers) (Crustaceans; are; T:often; vital elements of the food chain)
Crustaceans Crustaceans
are are
herbivores, carnivores, or scavengers
T:often vital elements of the food chain