[填空题]

• A. Cloud-to-ground lightning occurring in the U. S.
• B. Types of lightning
• C. Cause of lighruing
• D. Differences between thunder and thunderstorm
• E. Frequencies of thunderstorms occurring in the world and the U. S.
• F. Shockwaves as thunder

Paragraphs 2 and 3 ______.

• A．Cloud-to-ground lightning occurring in the U. S.
• B．Types of lightning
• C．Cause of lightning
• D．Differences between thunder and thunderstorm
  E Frequencies of thunderstorms occurring in the world and the U. S.
  F Shock waves as thunder

Revolutionary innovation is now occurring in all scientific and technological fields. This wave of unprecedented change is driven primarily by advances in information technology, but it is much larger in scope. We are not dealing simply with an Information Revolution but with a Technology Revolution.
To anticipate developments in this field, the George Washington University Forecast of Emerging Technologies was launched at the start of the 1990s. We have now completed four rounds of our Delphi survey -- in 1990,1992,1994,and 1996 -- giving us a wealth of data and experience. We now can offer a reasonably clear picture of what can be expected to happen in technology over the next three decades.
Time horizons play a crucial role in forecasting technology. Forecasts of the next five to ten years are often so predictable that they fall into the realm of market research, while those more than30 or 40 years away are mostly speculation. This leaves a 10-to 20-year window
A. 5 - 10 years.
B. 10 - 20 years.
C. 20 - 30 years.
D. 30 - 40 years.