填空题

• A. evaporation
• B. water cycle
• C. complicated process
• D. ever-going-on process
• E. rainfall
• F. ground water
• G. vapor
• H. transpiration
• I. high land
• J. formation of clouds
  K. formation of rain
  L. cold air
  M. drops of rain
  N. absorbed by soil
  O. porous rock layer
  P. non-porous rock layer
  Q. accumulation of water
  R. process of water cycle

不渗水岩层( ) 冷空气( )