第1题：填空题:The importance of agriculture cannot be overstated. More than 50 percent of the worlds labor force is employed in agriculture. The distribution in the early 1980s ranged from 67 percent of those employed in Africa to less than 5 percent in North America. In Western Europe, the figure was about 16 percent; in Eastern Europe and the Soviet Union, about 32 percent; and in Asia, about 68 percent. Farm size varies widely from region to region. Recently the average for Canadian farm
