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 simplicity, answers should be in all lower cased letters.
PROBLEM: Category: OLYMPIC HOST COUNTRIES 
Clue: 3 of the 6 countries that have hosted both the summer & winter Olympics

SOLUTION: united states, canada, france, germany, italy & japan

PROBLEM: Category: AUTHORS 
Clue: In January 1999 this author issued a public statement reminding the world the third millennium really begins Jan. 1, 2001

SOLUTION: arthur c. clarke

PROBLEM: Category: SKYSCRAPERS 
Clue: After a construction boom fueled by oil & gas money, this capital city now has Europe's tallest building

SOLUTION:
moscow