The correct answer is Sigmund Freud. His studies on psycho-neuroses around the 20th century is considered to be the basis of psychology and psychiatry.
Answer:
(in some cosmological theories) nonluminous material that is postulated to exist in space and that could take any of several forms including weakly interacting particles (cold dark matter) or high-energy randomly moving particles created soon after the Big Bang (hot dark matter).
Explanation:
The ecological effects of acid rain are most clearly seen in aquatic environments, such as streams, lakes, and marshes where it can be harmful to fish and other wildlife. As it flows through the soil, acidic rain water can leach aluminum from soil clay particles and then flow into streams and lakes answer is d