A、It became easier for factory owners to find workers and customers. B、Manufacturers had to employ more highly skilled workers.

Industrialization came to the United States after 1790 as North American entrepreneurs increased productivity by reorganizing work and building factories. These innovations in manufacturing boosted output and living standards to an unprecedented extent; the average per capita wealth increased by nearly 1 percent per year—30 percent over the course of a generation. Goods that had once been luxury items became part of everyday life.
    The impressive gain in output stemmed primarily from the change of the way in which workers made goods. Since the 1790’s, North American entrepreneurs—even without technological improvements— had broadened the scope of the work system that made manufacturing more efficient by distributing materials to a succession of workers who each performed a single step of the production process. For example, during the 1820’s and 1830’s the shoe industry greatly expanded the scale and extent of the work system. Tens of thousands of rural women, paid according to the amount they produced, fabricated the uppers of shoes, which were bound to the soles by skilled shoemakers in dozens of Massachusetts towns, whereas previously skilled shoemakers would have made the entire shoe. This system of production made the employer a powerful shoe boss and eroded workers’ control over the pace and conditions of labor. However, it also dramatically increased the output of shoes while cutting the price.
    Entrepreneurs created an even more important new organization, the modern factory, which used power-driven machines and assembly-line techniques to turn out large quantities of well-made goods. As early as 1782 the creative inventor Oliver Evans had built a highly automated, laborsaving flour mill driven by water power. His machinery lifted the grain to the top of the mill, cleaned it as it fell into containers known as hoppers, ground the grain into flour, and then conveyed the flour back to the top of the mill to allow it to cool as it descended into barrels. Subsequently, manufacturers made use of new improved stationary steam engines to power their mills. This new technology enabled them to build factories in the nation’s largest cities, taking advantage of urban inexpensive labor, good transportation networks, and eager customers.
    16.What is the talk mainly about?
    17.Why does the speaker mention the shoe industry?
    18.According to the talk, how did later mills differ from the mill built by Oliver Evans?