Abird eats a caterpillar ate a tree leaf the tree is an example of a

a: producer

b: consumer

c: decomposer

d: carnivore

c. heat from the poles back down towards the equator.

the peaceful equids (horses, donkeys and zebras) were enslaved by the human race to do our bidding -- sorry, domesticated -- several thousand years ago, and since that time they've been an invaluable resource for transportation, agriculture, warfare, companionship and sometimes-horrifying entertainment.