The gist of a story is the main idea of a story. It is like a short summary.
True, use a colon rather than a comma to follow a salutation in a business letter.
Dear Ma. Johnson:
Dear Dave,
Introvert= Less sociable, keeps more to self
Extrovert= outgoing, sociable
Personally-
I would say I am about 60% an introvert and 40% and extrovert. When I am at school, I try to keep more to myself. I like to be by myself and focus on schoolwork. When I am with friends I tend to be more extroverted because I am comfortable with them. I talk more, not only to them, but also to people i do not know.
