sentence2_structure: A primary role of decomposers in an ecosystem<>is<>that they cycle matter$$$they<>cycle matter<>
sentence1: describe the flow of matter and energy through ecosystems (e.g., the hydrologic cycle, the carbon cycle) and explain the relationship of these flows to landforms, climate, soils, and vegetation;
sentence2: A primary role of decomposers in an ecosystem is that they cycle matter by returning carbon and other matter to the ecosystem.
question: What is a primary role of decomposers in an ecosystem?