TASK DEFINITION: In this task, you're given an open-domain question. Your task is to provide an answer to the given question. There is only one unique answer for each question. Your answer should be short, and refer to an entity, date, number, etc. Do not put your answer in the context of a sentence.
PROBLEM: Who wrote the song flight of the bumblebee?

SOLUTION: Nikolai Rimsky-Korsakov

PROBLEM: Who discovered the center of the milky way galaxy?

SOLUTION: a team of radio astronomers, led by Joseph Lade Pawsey

PROBLEM: What kind of fuel do space rockets use?

SOLUTION:
Rocket Propellant-1