instruction:
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.
question:
What word is used in mathematics to mean if and only if?
answer:
if and only if

question:
The Khorat Plateau forms part of which Asian country?
answer:
thailand

question:
Who starred as ageing actress 'Margo Channing' in the 1950 film 'All About Eve'?
answer:
bette davis