In history such as World History? You should be able to distinguish the trends and differences in different periods say "Period 1 vs. Period 2" where each period represents a different range of years (in AP World History I learned it with 6 periods but it varies from year to year of when it is taught)
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.
Answer:
It is important because it's the difference between giving and recieving.
Explanation:
The definition of refugees is "people fleeing conflict or persecution". The definition of economic migrants is "movement of people from one country to another to benefit from greater economic opportunities in the receiving country". The United States, Canada, and European countries turn refugees away because they are fleeing conflict, could potentially bring that conflict or cause conflict to the new place, and don't give back in a major way once they are granted permission to stay. Whereas, economic migrants are, mostly, not fleeing conflict so the place wouldn't have to fear foreign affairs and consequences, as well as the fact that the migrants will, in some way, give back to them in a way that benefits the place in multiple ways or a major way (such as giving back in the form of exceptional work or labor). This is why they have policies that distinguish between refugees and economic migrants - they want to invite in the people that will benefit them whilst keeping those who won't benefit them out.
Stage 1
Low
Growth
<span> Very high CBR, Very high CDR, <span>Very low NIR
Stage 2
High Growth
High CBR, Rapidly declining CDR, Very high NIR
Stage 3
Moderate Growth
Rapidly declining CBR, Moderately declining CDR, Moderate NIR
Stage 4
Low Growth
Very low CBR, Low or slightly increasing CDR, zero or negative NIR</span></span>
