Answer:
Septic tanks and oxidation ponds
Explanation:
These system of wastewater treatment and disposal are not too feasible in large municipalities because of the presence of sewer system that has been made available by government, in order to mitigate the possibilities of transmitting enteric diseases that are very harmful to human health.
The common component of air pollution is particulate matter (PM). This is a complex mixture of extremely small particles and liquid droplets.
The major components of PM are sulphates, nitrates, ammonia, sodium chloride, black carbon, dust particles and water. PM comes from dust , soot, smoke, industry and vehicle exhaust as well as complex chemical reactions with other pollutants.
Burning of fossil fuels produces sulphur dioxide . It is a colorless gas that pollutes the air and can cause health problems affecting the respiratory system.
Electron cloud modle should be the answer
Sexual reproduction is a form of reproduction where two gametes fuse together. Each gamete contains half the number of chromosomes of normal cells. They are created by a specialized type of cell division, which only occurs in eukaryotic cells, known as meiosis.
So i'm gonna say that the answer is..B. helped maintain a slow rate of evolutionary change.
