The twentieth-century life-expectancy revolution occurred when scientists were able to:
A) cure or prevent many infectious diseases.
B) slow the progress of many chronic diseases.
C) make inroads in curing heart disease.
D) allow people to live happier lives.

Question

Quizplus · Accepted Answer

The twentieth-century life-expectancy revolution was primarily due to the prevention and cure of infectious diseases such as smallpox, measles, and polio through the development of vaccines and antibiotics. This was a major factor in extending the average lifespan of people in many countries.

The Twentieth-Century Life-Expectancy Revolution Occurred When Scientists Were Able To