TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM: Which composer's oratorios include 'The Kingdom' and 'The Dream of Gerontius'?

SOLUTION: the dream of gerontius

PROBLEM: Joseph Addison and Richard Steele founded (in 1711), and Boris Johnson edited, which British magazine?

SOLUTION: boris johnson

PROBLEM: Who was the Russian author of 'Taras Bulba' and 'Dead Souls'?

SOLUTION:
dead souls