A typhoon is one of the most destructive disasters in nature. Some studies have shown that by spraying water droplets into the air, the reflection of daylight by the clouds over the area where the typhoon is formed, the typhoon will not be able to gather enough energy. The advance of the typhoon, thus avoiding greater damage. Which of the following should be added as a prerequisite for the conclusion of the above conclusion? ['Water droplets sprayed into the air can re-gather above the clouds.', 'Artificial clouds will affect rainfall in adjacent areas.', 'When a typhoon passes, it is often accompanied by strong convective weather such as gale and heavy rain.', 'The driving force of the typhoon comes from the heat generated by sunlight on the surface of the sea.']