What do all the names of all the continents have in common?

Almost all the continents have names starting with the letter A. We have Asia, America (north and south), Africa, Australia, Antarctica. Only Europe does not start with A. Sometimes Europe and Asia are combined into the continent of Eurasia (since the distinction between Europe and Asia is political rather than physical) but alas, that too starts with an E. I could still say that every single name of a continent starts with one of the first 5 letters of the alphabet.