Most forest fires and wildfires are natural. They clear away debris, old brush, and dying trees, leaving heartier trees better able to grow. Certain trees, in fact, produce seeds only when fire heats them. If the fire removes thick shrubs and undergrowth, the water supply increases, aiding other plants and local animals. Fire also may kill predatory insects or pests that live on and damage otherwise healthy trees. Write two sentences in which you identify the main idea and at least one supporting detail of this paragraph.