填空题. Almost every new innovation goes through three phases. When 1 introduced into the market, the process of 2 is slow. The early models are expensive and hard to use, and perhaps even unsafe. The economic 3 is relatively small. The second phase is the explosive one, 4 the innovation is rapidly adopted by a large number of people. It gets cheaper and easier to use and becomes something familiar. And then in the third stage, diffusion of the innovation slows down again, as it permeates out across the economy. During the explosive phase, whole new industries spring up to produce the new product or innovation, and to 5 it. For example, during the 1920s, there was a dramatic acceleration in auto production, from 1.9 million in 1920 to 4.5 million in 1929. This 6 was accompanied by all sorts of other essential activities necessary for an auto-based nation: Roads had to be built for the cars to run 7 ; refineries and oil wells, to provide the gasoline; and garages, to repair them. The same pattern is 8 repeated again and again with innovations. The construction of the electrical system required an enormous early investment in generation and distribution 9 . The introduction of the radio was followed by a buying spree (无节制的狂热行为) by Americans that quickly brought radios into almost half of all household by 1930, up from 10 none in 1924. A. impact B. adaptation C. initially D. where E. on F. nearly G. service H. blossom I. which J. by K. adoption L. boom M. pattern N. historically O. capacity