What is a poem or stanza of four lines called?

Complete the title of Barbara Tuchman's Pulitzer Prize-winning book about the start of World War I: "The Guns of ___." In 1928, Colombian banana plantation workers went on strike against which American company? By custom, an American flag flies over which French hero's grave in Paris? By December 15, 1791, the states had ratified the first 10 amendments to the Constitution, known collectively as what? Crudites are vegetables served in what way? By definition, what does a carnivore eat? What do you do at an ingress? By definition, ungulates are mammals with what?