The warming of the Pacific Ocean creates weather patterns that (17) _________ the world. When the waters warm, the (18) __________ of rainfall in Indonesia and the surrounding regions decreases. Australia could even experience a drought. (19) __________ the other hand, Chile, which borders the Pacific Ocean, is preparing for severe rainstorms. In Pakistan and northwestern India, the weather pattern makes the monsoon season weaker and makes the area much drier.
This phenomenon is called El Nino and is used by weather (20 __________ to make long range weather predictions. Forecasters know that El Nino will bring unusually heavy rains to southwestern part of the United States and make the (21) __________ part of the country drier.
El Nino itself used to be predictable. It would occur every two or seven years. But now, the weather pattern is becoming more (22) __________. Scientists are unsure of the reason of this change.
15. A. effect B. affect C. infect D. expect
16. A. amount B. number C. great deal D. percent
17. A. In B. At C. For D. On
18. A. forecast B. forecasting C. forecasters D. forecasts
19. A. center B. centralize C. centre D. central
20. A. constant B. constancy C. inconstant D. inconstancy