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.

[Q]: Who wrote and starred in the comedy series It's A Square World?
[A]: michael bentine

[Q]: In which book does the character Melanie Wilkes appear?
[A]: gone with the wind

[Q]: Under standard conditions, the lightest and least dense of all metallic elements is?
[A]:
lithium