They are developed countries because the people there are healthy and educated.
Answer:
Eutrophication is the result of excess nutrients, particularly nitrogen and phosphorus, entering the water system.
When sediment is pressed together, the matrix is often cemented by such things as silica (SiO2) and calcium carbonate (CaCO3). These natural cements are usually precipitated by circulating groundwater within permeable rocks such as sandstone and conglomerate.
It's a dry northeastern wind on the West coast of Africa
