Question

Which sentence from the passage best supports the idea that before Salk's team, medical researchers had been unable to combat polio effectively?


A. Building on the research of previous scientists and doctors, Salk developed a polio vaccine by growing large numbers of the virus in test tubes.


B. Analyzing their test results, Salk and his team were thrilled to see that their vaccine caused the immune system to produce polio antibodies without making a person ill.


C. In 1952, the United States dealt with 57,000 cases of polio—the most cases ever in a single year.


D. The next year, scientists announced that the vaccination trial had been a success: the vaccine prevented polio infections in 80% to 90% of people

Answer 1

The sentence from the passage that best supports the idea that before Salk's team, medical researchers had been unable to combat polio effectively is the sentence in option A.

"Building on the research of previous scientists and doctors, Salk developed a polio vaccine by growing large numbers of the virus in test tubes."

The part of the sentence above suggests that there was research done previously by scientists and doctors. Salk's team is building on these previous researches, which hints that these previous research are unsuccessful, but gives enough information on what Salk's team needs to do to combat polio effectively.

Learn more about supporting sentences at https://brainly.com/question/1741847

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