Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Context: The Pier 21 Society opened an interpretive centre in part of the former immigration facility in 1999. 
 Question: What year was Pier 21 opened?
1999

Context: After Attila's death in 453 AD, his Empire crumbled and its remains were ruled by his three sons, Ellac, Dengizich and Ernak. 
 Question: Who was the brother of Ellac?
dengizich

Context: Robert P. Baldwin (October 19, 1917 -- April 7, 1994) was an Army Air Corps and United States Air Force pilot during World War II and Korea. 
 Question: With which military branch did Robert P. Baldwin hold a command?

united states air force