<span>D. the poverty threshold. This differs based on geography (certain areas of the country are more expensive to live in than others) and family size.</span>
It’s a higher fertility rate high rate of industrialization and longer life expectancy
The variable is the group that was given caffine, because thats what the doctors manipulated. They possibly altered the natural memory of the participants by giving them caffine. A more specific variable could be how much caffine each participant is given and what time are they given it.
In recent time, the aforementioned issues were replaced with
discrimination, slavery and genocide of many Native American. Slavery had been
one of the biggest problems in the United States that had rooted to racial discrimination
and segregation among the citizens of the country as well as it contributes to
genocide to many Native American families that were “civilized” by the current
culture.
