Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
--------
Question: Which 1970s musical film starred Angela Lansbury as a trainee witch?

Answer: angela lansbury


Question: Which Renaissance artist's life was fictionalised in the book 'The Agony and the Ecstasy' subsequently made into a film?

Answer: the agony and the ecstasy


Question: What is common name of the clear flammable early anaesthetic liquid with the formula C2H5OC2H5 (or CH3-CH2-O-CH2-CH3)?

Answer:
diethyl ether