Drinking water should not contain eggs and larvae of worms, microbes that can cause epidemic diseases. Water pollution often occurs due to the ingestion of open excrement of animals and humans containing E. coli. If the number of these pathogenic (pathogenic) microbes exceeds the MPC (maximum permissible concentration), the water is considered contaminated and unfit for drinking. Water should also have a harmless chemical composition: it should not contain toxic and radioactive compounds. An important chemical indicator is water hardness. It depends on the content of calcium and magnesium salts. Water should be palatable, clear, transparent, colorless, odorless and tasteless, free from foreign substances.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.