Control because it is used for observation to the rest of the experiment (:
The answer would be A. When supply exceeds demand
This is because there is plenty supply for the forest without animals dying from things such as, lack of food.
When demand exceeds supply it throws an ecosystem off because some animals aren't getting the food they need and therefor dying. So that eliminates answers C. and D.
When supply and demand are both 0 that means that there are no animals to demand and there are no supplies for demand leaving no sustainable ecosystem.
Groups of specialized cells cooperate to form a tissue, such as a muscle. Different tissues are in turn grouped together to form larger functional units, called organs. Each type of cell, tissue, and organ has a distinct structure and set of functions that serve the organism as a whole.
Answer:
cosmic microwave background
The cosmic microwave background (CMB) is thought to be leftover radiation from the Big Bang, or the time when the universe began. As the theory goes, when the universe was born it underwent a rapid inflation and expansion.
Explanation: