Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 25 to 29. Fill in the appropriate word in question 29

  The warming of the Pacific Ocean has created weather pattern (25)_______ strongly affect the world. When the water is warm, the amount of rainfall in Indonesia and the surrounding regions decreases. Australia could (26)_______ experience a drought in many parts. On the other hand, Chile (which borders the Pacific Ocean) is preparing for severe 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 (27)_______ weather forecasters to make long-range weather predictions. They also know that El Nino will bring unusually rain 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 (28)_______ know about the coming weather with certainty. Now everything has become completely different.

  El Nino itself used to be predictable. 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 (29)_______ on the global scale either.