Given an trivia question precisely answer the question with a word/phrase/name. External resources such as Wikipedia could be used to obtain the facts.

Which king experienced regicide at the hands of Shakespeare's Macbeth?
king duncan

Broadcast on live TV, what Dallas nightclub owner shot and killed total asshat Lee Harvey Oswald?
jack ruby

Who was the presenter of the UK television series 'The Old Grey Whistle Test' from 1972 to 1978?
bob harris