instruction:
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.
question:
Category: GEOGRAPHY 
Clue: This Sudanese capital is located at the junction of the Blue & the White Nile
answer:
khartoum


question:
Category: U.S. RIVERS 
Clue: The Falls of Saint Anthony stop this mighty river from being navigable north of St. Paul, Minnesota
answer:
the mississippi


question:
Category: YOU KNOW WHAT THEY SAY... 
Clue: You might be just "banging your head against the wall" when you "flog a dead" one of these
answer:

horse