instruction:
Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
question:
What American swimmer won eight gold medals at the 2008 Olympics?
answer:
2008 summer olympics


question:
Chep Lap Kok airport is located where?
answer:
hong kong international airport


question:
Also containing Garlic and salt, what is the name of the Greek appetiser, the primary ingredients of which are yoghurt and cucumber?
answer:

greek