Addiction: Central nervous system (CNS) stimulants are addictive, even if they are not abused. Many factors, including the patient's personal history, the type of stimulant that is being taken, the dose of the drug, and duration of use, influence how likely an individual is to become addicted.
The source of all waves - mechanical or electromagnetic - is something that is vibrating. Matthew Donovan.
The sun is the source of all energy, heat and light. The amount of sunlight in an area determines what living thing can survive there. For example, the upper part of the sea or ocean receives a lot of sunlight. It is therefore warmer than the ocean floor, which has little or no light at all.