In order for an ecosystem<span> to be self-</span>sustaining, it must have<span> a continuous flow of energy and be able to recycle materials</span>
Answer:
number 1: heat from the sun or solar energy
Explanation: Spotted fur because it helps the serval to blend in and punce on unexpecting prey
C because oxygen was a byproduct of photosynthesis and proved to be EXTREMELY important in the atmosphere.