Increases in life expectancy in the United States during the twentieth century were due primarily to
a. the control of childhood and infectious diseases.
b. the fitness boom.
c. increased use of vitamin supplements.
d. the defeat of chronic illness.

A. the control of childhood and infectious diseases.

Explanation: Life expectancy began to rise due to better sanitation and education in the twentieth century

i do believe   by (keeping an organized record of all sources he or she referenced)good luck.

explanation:

the old way of life was represented by superstition, an angry god, and absolute submission to authority. the thinkers of the age of reason ushered in a new way of thinking. this new way championed the accomplishments of humankind. individuals did not have to accept despair. science and reason could bring happiness and progress. kings did not rule by divine right. they had an obligation to their subjects. europeans pondered the implications for nearly a century. americans put them into practice first.