D. Cholinergic antagonists
Vitamin <span>a class of diverse organic substances that occur in many foods in small amounts and are necessary in trace amounts for the normal metabolic functioning of the body</span>
We live<span> in the Holocene.
Hope this helped :)</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>
