My guess would have to be hydropower, since water isn't an un natural substance
Answer: The endocrine system sends chemicals called hormones through the bloodstream to change short-term and long-term activities in the body
Explanation: Endocrine system is a system made up of glands that produce and secrete chemical signal called hormones which travel through the bloodstream to the target cell where they exert their effects.
A hormone is a chemical messenger secreted by an endocrine gland. Long-term activities in the body influenced by hormones include growth and development.
Answer:
Negative growth rate is when a population's average number of deaths is greater than its average number of births. Zero growth rate is when the average number of deaths equals the average number of births.
Explanation:
Tar sands pits , sorry if I got this wrong
Sweat glands. :)
Perspiration leaves the body through the sweat glands.
