What was one of the challenges Dr. Salk faced in his attempt to create a polio vaccine? (10 points) a
b
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Dr. Salk did not have enough money to pay for his research and supplies.
Dr. Salk had to create one vaccine that was effective against three different viruses.
Dr. Salk had to convince government officials to allow him to test the vaccine.
Dr. Salk's idea for a vaccine was not supported by other scientists and physicians.
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d
Question 4(10 points)
Read the entry on Jonas Salk from Compton's Encyclopedia/The Britannica School Edition, and answer
Compton's Encyclopedia