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