is the number of people living in a square mile. In the future, economically developed nations may not have enough money to take care of older citizens because of . In low-income nations, is one reason for the low standard of living. Options for “___ is the number of people living in a square mile:

a. population density
b. population control
c. population growth

Options for “In the future, economically developed nations may not have enough money to take care of older citizens because of:

a. immigration
b. underpopulation
c. urbanization

Options for “In low-income nations, is one reason for the low standards of living:

a. overpopulation
b. population limits
c. underpopulation