Since the early twentieth century, the life expectancy of Americans has
A) increased by more than 10 years.
B) increased by more than 20 years.
C) increased by more than 30 years.
D) increased by more than 40 years.
Question 2
Heart disease, cancer, and diabetes are examples of
A) chronic disease.
B) hereditary disease.
C) communicable disease.
D) acute disease.
