Identify the three main ecological groups in every ecosystem. (在每个生态系统中，每个生物都有他们的生物角色，主要有哪三种生物角色？）

·producers or autotrophs (生产者也叫自养者）， they can manufacture organic compounds, such as glucose , from simple inorganic compounds, such as carbon dioxide,using an abiotic energy source, such as sunlight, through their energy -transforming actions, photosynthesis( 光合作用）。

·Consumers or heterotrophs (消费者也叫他养者）are those that must obtain their energy by eating other organisms or parts of them.

·Decomposers(分解者）are various species of fungi and bacteria (真菌和细菌）. Decomposers are heterotrophs (他养者）。they convert the organic matter of dead organisms into a simple form that can be taken up by producers.

What's the difference between decomposers and detritivores( 分解者和腐生生物有什么区别）？

Detritivores take in material and then absorb the products of digestion. They differ from decomposers in that decomposers first break down the organic matter outside their bodies by releasing enzymes(酶）and then they absorb some of the products.