You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.

[Q]: Category: CABINET OFFICERS 
Clue: He was the last Secretary of State to serve in the post under 2 presidents
[A]: henry kissinger


[Q]: Category: WORLD LEADERS 
Clue: Unopposed, he was elected to his 5th term as president in 1998; he's been in power since 1959
[A]: fidel castro


[Q]: Category: SCIENCE WORD ORIGINS 
Clue: Coined by the chemist J.B. van Helmont, the word gas comes from this Greek word meaning "unformed mass"
[A]:
chaos