The first polio vaccine was the inactivated polio vaccine. It was developed by Jonas Salk and came into use in 1955. The oral polio vaccine was developed by Albert Sabin and came into commercial use in 1961. They are on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system.
How many mountain ranges are shown on the map? Name the three that are in the Western Hemisphere. Eight mountain ranges; Rocky Mountains, Andes Mountains, and the Appalachian mountains. Name the five labeled mountain ranges in the Eastern Hemisphere. Himalayas, Atlas Mountains, Alps, Caucasus Mountains, and the Ural Mountains. Which mountain range acts as a natural border between Europe and Asia
The southern or main range of the Eastern division is known by the French as the Saharan Atlas. On its western extremity it is linked by secondary ranges to the mountain system of Morocco. The Saharan Atlas is essentially one chain, though known under different names: Jebel K'sur and Jebel Amur on the west, and Jebel Aures in the east. The central part, the Zab Mountains, is of lower elevation, the Saharan Atlas reaching its culminating point, Jebel Shellia (7611 ft. above the sea), in the Aures. This range sends a branch northward which joins the Mejerda range of the Maritime Atlas, and another branch runs south by Gafsa to the Gulf of Gabes.