The warming of the Pacific Ocean has created weather patterns (1)    strongly affect the world. When the water is warm, the amount of rainfall in Indonesia and the surrounding regions decreases. Australia could (2)     experience a drought in many parts. On the other hand, Chile  (which borders the Pacific Ocean) is preparing  for (3)     rainstorms. In Pakistan and northwestern India, the weather pattern makes the rainy season weaker and makes the area much drier. This happening is called El Nino and is used by weather forecasters to make long-range weather predictions. They also know that El Nino will unusually bring heavy rains to the southwestern part of the United States and make the central part of the country drier at the same time.

According to research, weather forecasters used to know about the coming weather with certainty. Now everything has become completely different. El Nino itself used to be (4)     . It would occur every two to seven years. But now, this weather pattern is becoming more frequent. We cannot say when and how often tornadoes or cyclones occur. Scientists are unsure of the reason for this (5)     on a global scale either.

(4) ..................

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