D. He has an aerator that pumps bubbles into the tank
There are some things that can prevent decay, one if them is ice, an example of that is a frozen mammoth, ice can prevent the body from decaying, another thing is amber, it can trap an insect and prevent it from decaying, lastly there is tar, a substance that covers thing in a black substance that prevents it from decaying.
Answer: Hey I will gladly help. I can't right now because you did not say what each pond is like. If you fix it, I will do it for you
Explanation:
Answer:
a. iris
Explanation:
iris is actually the structure of the eye that regulates the amount of light passing to the visual receptors of the eye
Lloyd came up with the idea of Tragedy of the Commons