C.
phytoplankton and zooplankton
I believe the answer should be mates...(2)
A decomposer breaks down and gains nutrients from dead organisms
I think that the Low-head hydropower involves small dams on minor rivers.
Low head hydropower plants are those that operate with a water level difference of 30 feet or less. The systems that generate electricity involve diverting water from a river that is delivered to a power house containing a turbine, generator or other equipment that convert mechanical energy to electrical energy.
Eugenics is the science of improving a population by controlled breeding to increase the occurrence of desirable heritable characteristics. The term eugenics was coined by British explorer and Charles’ Darwin’s’ cousin Francis Galton in 1882, who is influenced by his cousins theory of natural selection. It comes from the Greek roots eu- means"good" and genos means "birth." It is known effort to improve the genetic makeup of a population. Galton believed that the human race could be improved by encouraging people who have "good" genes to marry early and have lots of children, and discouraging people with "bad" genes from procreating at all.