Misc: who has had hits with heartbeat, 5-6-7-8 and tragedy?

Questions

Which film role links Mary Elizabeth Mastrantonio, Olivia de Havilland and Audrey Hepburn?

Which crime fiction writer's titles have a numerical theme. e.g. 1 for the money, 2 for the Dough?

Name the English king who met King Francis 1st of France on the Field of the Cloth of Gold.?

Circle, Parabola and Hyperbola are three 3 of the four curves known as the conic sections. Name the fourth.?

In which U.S. state is Fort Knox?