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 consistency, answers should be in all lower cased letters.
question:
Category: NONFICTION
Clue: This 1988 bestseller was subtitled "From the Big Bang to Black Holes"
answer:
a brief history of time

question:
Category: SPORTS FIRSTS ON THE FIRST
Clue: On February 1, 1970 Dave Balon pulled off his first one of these in his pro hockey career
answer:
hat trick

question:
Category: ALL THINGS BRITISH
Clue: In 1997 PM Blair swapped homes with the Chancellor of the Exchequer & now lives at No. 11 on this street
answer:
downing street