六级改错冲刺模拟题（3）

   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