Almost every new innovation goes through there phases. When initially
introducing into the market, the process of adoption is slow. The early 79. ______
models are expensive and hard to use, and perhaps even unsafe. The
economic impact is relatively great. 80. ______
The other phase is the explosive one, where the innovation is rapidly 81. ______
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 (传播，扩
散) of the innovation slows down again, as if it permeates out across the 82. ______
economy.
During the third phase, the whole new industries spring up to produce 83. ______
the new product or innovation, and to service it. For example, during the
1920s, there is a dramatic acceleration in auto production, from 1.9 million in 84. ______
1920 to 4.5 million in 1929. This boom was accompanied with all sorts of 85. ______
other essential activities necessary for an auto-based nation:
Roads had to be built for the cars to run on; refineries and oil wells, to
provide the gasoline; and garages, to repair it. Historically, the same pattern 86. ______
is repeated again and again with innovations. The construction of the
electrical system requested an enormous early investment in generation and 87. ______
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 88. ______
almost half of all households by 1930, up from nearly none in 1924.