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What is the Text Structure for the passage
No one knows exactly what causes tornadoes, but some scientists believe that when warm air meets cold air, a tornado may form. The reason for this is that the warm air is lighter than the cold air, so it rises up fast and meets different winds moving different directions. Under the right conditions, this can cause a tornado. Though there is still much mystery surrounding tornadoes, many people believe that when warm moist air meets cool dry air, tornadoes can result.
What is Cause and Effect