Fill in each numbered blank with one suitable word or phrase Any change in one part of an ecosystem can cause changes in other parts. Droughts, storms and fires can change ecosystems. Some changes ___1___ ecosystems. If there is too ___2___ rainfall, plants will not have enough water to live. If a kind of plant dies off, the animals that ___3___ it may also die or move away. Some changes are good for ecosystems. Some pine forests need ___4___ for the pine trees to reproduce. The seeds are sealed inside pinecones. Heat from a forest fire melts the seal and lets the seeds___5___. Polluting the air, soil, and water can harm ecosystems. Building ___6___ on rivers for electric power and irrigation can harm ecosystems ___7___ the rivers. Bulldozing wetlands and cutting down ___8___ destroy ecosystems. Ecologists are working with companies and governments to find better ways of ___9___ fish, cutting down trees, and building dams. They are looking for ways to get food, lumber, and other products for people ___10__