四级冲刺练习阅读162

　　How, then, can some land areas receive more than 400 inches of rain per year? How can several inches of rain fall during a single storm in a few minutes or hours? The answer is that rain-yielding air masses are in 18 , and as the driving air mass moves on, new mist air takes its place.

　　The basic source of most water vapor is the ocean. Evaporation, vapor transport, and rainfall make up the 19 movement of water from ocean to atmosphere to land and back to the sea. Rivers return water to the sea. In an underground area of the cycle, flowing bodies of water 20 some water directly into rivers and some directly to the sea.

　　A. contains B. view C. discard D. movement

　　E. time F. amazing G. continuous H. roughly

　　I. amusing J. motion K. rudely L. vision

　　M. invisible N. suddenly O. discharge

　　II. B 12. F 13. E 14. H 15. A 16. M 17. N 18. J 19. G 20. O