The answer is the Nile River
Answer:
Proper cleanliness of water..
<span>It's is the second one. The waste materials generated by one organism are often reused by other organisms.Mass, or matter, is conserved in all physical and chemical changes. Matter is not created or destroyed within ecosystems, it only undergoes physical or chemical changes. One example of this process is that the waste materials generated by one organism are often reused by other organisms as food or nutrients.</span>
