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:
A series diverges if the limit is plus or minus infinity, or if the limit does not exist.
They must have the same rights to become a citizen as someone born in the U.S
Answer:
dear sir I am new to the same day
