Name The Year: U.S. sub locates missing hydrogen bomb in Mediterranean.?

Questions

What U S states were named for the Sioux word "friend"or"ally?

What vitamin is most commonly added to milk, because it is not found in milk naturally?

What vitamin is sometimes called the 'sunshine vitamin?

What kind of clay can potters heat to a higher temperature earthenware or stoneware?

What kind of tradesman uses a 'plunger?