Answer:
The section "Three Roles for Living Things" is mostly about the different functions or roles that living things play in ecosystems. This section highlights three primary roles that living organisms fulfill: producers, consumers, and decomposers. Producers, such as plants, use sunlight to convert carbon dioxide and water into food through photosynthesis. Consumers, including animals, obtain energy by consuming other organisms. Decomposers, like fungi and bacteria, break down dead organic matter and recycle nutrients back into the ecosystem. The section explains how these roles are interconnected and essential for the overall functioning of ecosystems.