What is a celebration marking a 10-decade anniversary called?

A causeway linking Bahrain and Saudi Arabia is named for which man who became Saudi king in 1982? A cautionary 1994 story listed 115 people who had died on which mountain, the highest in New England? A cease-fire agreement to end which war was signed in Paris on January 27, 1973? A cedilla, a circumflex and a macron are all examples of which kind of mark? Which keyboard instrument, famous from Tchaikovsky's "Dance of the Sugar Plum Fairy," makes its bell-like sound with ha… What is the name of the cell formed by the union of two gametes? Which tower, built as the centerpiece of the 1962 World's Fair, took its inspiration from science-fiction art and a Ger… A pair of century-old paintings by C.M. Coolidge sold for $590,400 at a 2005 auction. What animals are shown playing po…