What word names a hard fruit stone or a cavity in the ground?

A World War II soldier, which civil rights leader murdered in Mississippi in 1963 is buried at Arlington? Which NFL team's logo shows a soldier's head in a blue three-cornered hat with red streaks? What is a solid figure having 10 faces called? What 11-letter word names a solid figure with 7 faces? What solid shape has six identical square faces? A song and a dance were named for which woman who swam the English Channel in 1926 and died at 98 in 2003? Which artist's song hit No. 1 in 1999, making her, at 52, the oldest woman to that point to top the Billboard Hot 100? The song "Summertime" ("and the livin' is easy") comes from which opera?