Misc: Tristan da Cunha is an island group in which ocean?

Questions

what does las vegas mean, in spanish?

which mobster first built a gambling resort in the nevada desert that became las vegas?

which city is home to nine of the 10 largest hotels in the world?

which is the lake that is half in california and half in nevada?

in "to kill a mockingbird", who played the character boo radley?