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
Map showing the location of the Atlas Mountains across North Africa. The basement rock of most of Africa was formed in the Precambrian (approximately 4.5 billion years ago) and is much older than the Atlas mountains lying in Africa.