instruction:
Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
question:
In 1864, the Dale Dyke Dam burst while being filled, leading to the death of 240 people in which British city?
answer:
dale dike reservoir


question:
Who married the woman who was to become Queen Beatrix of the Netherlands, on 10 March 1966?
answer:
beatrix


question:
21 October, 1833 saw the birth of Swedish scientist Alfred Nobel, who amassed his considerable fortune following his invention of what?
answer:

alfred nobel