All plant and animal groups existing together and the physical factors with which they interact compose an ecosystem<span>.</span>
Answer:
a kid crying
Explanation:
it brings more stress which higher due blood pressure even more !
Answer: "To move substances against a concentration or electrochemical gradient, a cell must use energy. Active transport mechanisms do just this, expending energy (often in the form of ATP) to maintain the right concentrations of ions and molecules in living cells."
