In the 1890s, German pioneer Otto Lilienthal made around 2,000 flights in what kind of engineless aircraft?

Which prefix meaning "self" can go before "biography" and "graph"? Which prefix meaning "star" can go before "naut" and "physics"? Which prefix meaning "below" can go before "standard" and "marine"? After the Mongol invasion of 1241, King Béla IV built a fortified town on Buda's Castle Hill in which country? The 20th Amendment, ratified in 1933, moved which event from March 4 to January 20? Which West African country with a hyphenated name was known as Portuguese Guinea until its independence in the 1970s? Before 1992, Illinois had last voted for a Democrat for president in 1964. Who was that candidate? In 1995, which M&M's color was replaced by blue after a public vote?