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Zack is online talking to his friend from school, Jahmaal. They are working on their homework together and studying for a test. Jahmaal says they should meet before class to review for the test.
How does Zack know this is Jahmaal?
Since they are friends from school, Zack should have Jahmaal's online name. Also, before he started talking to Jahmaal online his parents should verify with Jahmaal's parents what his online name is.