What cave, found in central Kentucky, is the world's longest cave system?

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What's the "toad" in traditional English toad-in-the-hole?

In the culinary world, what does "Amuse-bouche" literally translate to in English?

Thomas Jefferson is depicted on what US coin?

Which smartphone was allegedly named after a Philip K. Dick character?

What was Tom Clancy’s first novel, publisher in 1984?

What is composer Vivaldi's first name?

By what other name is Lac Leman known?

What rare Earth element is the second most abundant one in the known Universe?

Who was the second man to walk on the Moon?

Which Disney's cartoon character's love interest is named Captain Li?

What singing duo originally billed themselves as "Caesar and Cleo"?

Who was the first person to make a public encyclopedia?

Terry Nichols was the co-conspirator in what major crime during the 1990’s?

Whose concert was the target of a terrorist attack in May, 2017, in Manchester, UK?

The Ishihara Test is a color perception test used to detect deficiencies for which colors?