Practice 9　　In the United States most people are simultaneously consumers and producers; they are also voters who help influence the decisions of the government. The mixture among consumers, producers and government changes constantly, making a dynamic rather than a static economy. In the last decade consumers have made their concern known and government has responded by creating agencies to protect consumer interests and promote the general public welfare. In another development, the population and the labor force have moved dramatically from farms to cities, from the fields to the factories, and above all to service industries, thus providing more personal and public services. In today's economy these providers of services far outnumber producers of agricultural and manufactured goods.　　Generally, there are three kinds of businesses: (1) those started and managed personally by single owners or single entrepreneurs; (2) the partnership where two or more people share the risks and rewards of a business, and (3) the corporation where shareholders as owners can buy and sell their shares at any time on the open market. This latter structure, by far the most important, permits the amassing of large sums of money by combining investment of many people, making possible large-scale enterprises.