Along with the Irish and the English setter, which breed, named after a Scottish duke, completes the best-known trio of setters?

Which of these is one of the three classical orders of ancient Greek architecture? Two of John Brown's sons were killed during his October 1859 attack on the federal arsenal at which site? Which artist's major works include "Synagogue at Safed" (1931) and "King David" (1951)? Along with the clavicle, which bone meets the humerus at the shoulder? Along with Bach and Beethoven, which composer completes the "Three B's" of classical music? Besides the United States and Guatemala, which country borders Mexico? Neptunium and plutonium are two of the three elements named after planets. What is the third? Along with crocodiles and alligators, which long-snouted reptiles make up the third family of the order Crocodylia?