What does a keystone species do and how would you recognize one in an ecosystem?

Landfills are waste disposal sites. they are often man-made depressions in the ground covered with a lining designed to prevent any leakage of waste materials. however, landfills can leak through the base resulting in negative impacts on the surrounding environments. what negative impact to the environment is caused by organic and inorganic constituents that are dissolved by rainfall in the landfills?

The same agricultural practices are used in every country of the world. select the best answer from the choices provided t f

What is a difference between systemic and pulmonary circulation? a. systemic circulation carries oxygenated blood to the lungs and pulmonary circulation carries deoxygenated blood to the body. b. systemic circulation carries deoxygenated blood to the lungs and pulmonary circulation carries oxygenated blood to the body. c. systemic circulation carries deoxygenated blood to the body and pulmonary circulation carries oxygenated blood to the lungs. d. systemic circulation carries oxygenated blood to the body and pulmonary circulation carries deoxygenated blood to the lungs.