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.

Category: ANCIENT GREEKS 
Clue: This actor of the 6th century B.C. is credited with introducing the use of masks on stage
thespis

Category: ONTARIO 
Clue: The Ambassador Bridge, world's largest int'l suspension bridge, links Windsor, Ontario & this city
detroit, michigan

Category: GEMS 
Clue: Color of a peridot

green