57.From the first paragraph, we learn that in old days the most important farming power was_______. (A)livestock (B)farmers (C)machines (D)extra laborers

60.In the last sentence of paragraph 3,"fewer but larger farms and fewer but more prosperous farmers" means ________. (A)hired help is seldom needed (B)productivity on the farms has been raised greatly (C)productivity on the farms has fallen sharply (D)more food is never needed