[单项选择]

Set 5
THE DOMESTICATION OF ANIMALS
1.The domestication of wild species led directly to denser human populations by yielding more food than the hunter-gatherer lifestyle could provide. In societies that possessed domestic animals, livestock helped to feed more people by providing meat, milk, and fertilizer, and by pulling plows. Large domestic animals became the societies’ main source of animal protein, replacing wild game, and they also furnished wool, leather, and land transport. Humans have domesticated only a few species of large animals, with "large" defined as those weighing over 100 pounds (45 kilograms). Fourteen such species were domesticated before the twentieth century, all of them terrestrial mammals and herbivores. The five most important of these are sheep, goats, pigs, horses, and cattle or oxen.
2.Small animals such as ducks, geese, rabbits, dogs, cats
A. weighing over 100 pounds
B. unpredictable behavior
C. ability to breed in captivity
D. living in a herd with a hierarchy