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:
The school is defined as one of the most important- formal agency of education which plays a major role in moulding the ideas, habits and attitudes of a child with a view to produce well balanced personalities: physically strong, mentally alert, emotionally stable, culturally sound and socially efficient.
I hope it's helpful!
Answer:
A commerical or ad/advertisement
