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: THE QUOTABLE EINSTEIN 
Clue: This "is more important than knowledge"

SOLUTION: imagination

PROBLEM: Category: McGRAW-HILL 
Clue: While growing up, one of Tim McGraw's heroes was this ballplayer whom he later learned was his father

SOLUTION: tug mcgraw

PROBLEM: Category: THAT'S ILLINOIS-ING 
Clue: Illinois' southernmost city, it shares its name with Africa's largest city (pronounced differently)

SOLUTION:
cairo