63.The word “This”(Line2,Para,4)refers to____ (A)some force (B)traffic jam (C)the force that causes offices to move in or out (D)the fact that companies gather in big cities

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