A person who writes music:
COMPOSER
A person who has been trained for travelling in space.
ASTRONAUT
A person who is very good at sports or physical exercise, especially one who competes in organized events.
ATHLETE
A member of a government or law-making organization:
POLITICIAN
An expert who studies or works in one of the sciences:
SCIENTIST
Someone who travels to places where no one has ever been in order to find out what is there.
EXPLORER
A person who imagines how something could be made and draws plans for it.
DESIGNER
A person who is in charge of a film or play and tells the actors how to play their parts.
DIRECTOR