A common resource (or the "commons") is any scarce resource, such as water or pasture, that provides users with tangible benefits but which nobody in particular owns or has exclusive claim to. A major concern with common resources is overuse, especially when there are poor social-management systems in place to protect the core resource.
It might have mold On The surface
Answer:
I think it might be heart, lungs, blood, arteries, veins, and muscle cells
Explanation:
<span>The tracheae possibly have evolved directly from the book lungs</span>
The organisms in a pond and the physical factors <span>influencing them best describe "an ecosystem" since this is a self-contained environment will multiple organisms. </span>
