Natural disasters that are associated with rivers, there are floods, congestion, erosion of the coast. Such rivers include the rivers of Western Siberia, the mountain rivers of the temperate zone. The reason is climate change and human activities. People struggle with these phenomena: they plant forests along the banks, blow up congestion, build dams
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.