jonas salk and polio\npolio is a viral disease that produces flu - like symptoms and may occasionally cause…

jonas salk and polio\npolio is a viral disease that produces flu - like symptoms and may occasionally cause muscle weakness or paralysis. throughout the first half of the twentieth century, the disease was common, and parents feared that their children would lose the ability to move their arms or legs. in 1947, dr. jonas salk began studying polio at the university of pittsburgh in search of an answer. he discovered three basic types of polio viruses and began to develop a vaccine that would protect against all three. testing began in 1952, with vaccinations eventually given to about two million children. the vaccine was shown to be effective and was put into general use in 1955. jonas salk became a hero and received an award from president dwight d. eisenhower.\nwhat is the main, or central, idea of the passage?\njonas salks vaccine for polio was tested in the early 1950s and put into general use in 1955.\njonas salk developed a vaccine that provided protection against the feared disease polio.\njonas salk discovered that there were three different viruses that caused the disease called polio.

jonas salk and polio\npolio is a viral disease that produces flu - like symptoms and may occasionally cause muscle weakness or paralysis. throughout the first half of the twentieth century, the disease was common, and parents feared that their children would lose the ability to move their arms or legs. in 1947, dr. jonas salk began studying polio at the university of pittsburgh in search of an answer. he discovered three basic types of polio viruses and began to develop a vaccine that would protect against all three. testing began in 1952, with vaccinations eventually given to about two million children. the vaccine was shown to be effective and was put into general use in 1955. jonas salk became a hero and received an award from president dwight d. eisenhower.\nwhat is the main, or central, idea of the passage?\njonas salks vaccine for polio was tested in the early 1950s and put into general use in 1955.\njonas salk developed a vaccine that provided protection against the feared disease polio.\njonas salk discovered that there were three different viruses that caused the disease called polio.

Answer

Brief Explanations:

The passage starts by introducing polio as a feared disease. Then it focuses on Jonas Salk's work: he studied polio, discovered virus types, developed a vaccine, tested it (with details like the number of children vaccinated), and the vaccine's effectiveness leading to its general use. The first option only highlights testing and general use time - it's too narrow. The third option only mentions the discovery of virus types - also too narrow. The second option encompasses Salk's development of the vaccine which protected against the feared polio, covering the main elements of the passage.

Answer:

Jonas Salk developed a vaccine that provided protection against the feared disease polio.