Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.

The rivers Axe, Brue, Cary, Parrett, eta, are in which English county?
castle cary

Who played Lionel Hardcastle in the TV series 'As Time Goes By'?
as time goes by

What British adventurer fought in the Arab Revolt?
arab revolt