TASK DEFINITION: You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For consistency, answers should be in all lower cased letters.
PROBLEM: Category: GOIN' MONACO A MONACO 
Clue: Citizens of Monaco are not admitted to the casino founded in 1856 in this district

SOLUTION: monte carlo

PROBLEM: Category: NONFICTION 
Clue: This 1988 bestseller was subtitled "From the Big Bang to Black Holes"

SOLUTION: a brief history of time

PROBLEM: Category: FACIAL EXPRESSIONS 
Clue: When you're kidding, you're said to have your "tongue in" this -- kind of hard to talk that way

SOLUTION:
cheek