Which Russian-American novelist published his early Russian-language works under the pen name V. Sirin?

Which plant, related to and sometimes confused with endive, has been used to flavor coffee since the 18th century? Which poet's annual Christmas greeting for 1949 featured the poem "On a Tree Fallen Across the Road"? Which pop artist of comics-inspired images was awarded the National Medal of Arts in 1995? Which longtime United Mine Workers president, later its president emeritus, died in 1969? Which scouring powder is named for a mighty Greek warrior who fought in the Trojan War? Which sea is bordered by Georgia on its eastern side and Bulgaria on its western side? Which singer, long associated with Key West and born on Christmas Day, recorded the song "Christmas Island"? Which small Virginia stream, about 30 miles from Washington, D.C., gave its name to two Civil War battles?