Answer:In 1947, Salk took a position at University of Pittsburgh, where he began conducting research on polio, also known as infantile paralysis. By 1951, Salk had determined that there were three distinct types of polio viruses and was able to develop a "killed virus" vaccine for the disease.
Explanation:
The study of earth, like map reading, locations on the map, countries, continents, seas/oceans/lakes, mountains/hills (best way I could explain it, sorry if it doesnt make sense)
Answer:
George Washington é o primeiro presidente dos Estados Unidos
B. The government should respect its citizens.
d. The government should teach its citizens how to become rich businessmen and productive contributors to society.
