Problem: In 1913, Elmer McCollum discovered the first vitamins, fat-soluble vitamin A, and water-soluble vitamin B (in 1915; now known to be a complex of several water-soluble vitamins) and named vitamin C as the then-unknown substance preventing scurvy. Lafayette Mendel and Thomas Osborne also performed pioneering work on vitamins A and B. In 1919, Sir Edward Mellanby incorrectly identified rickets as a vitamin A deficiency because he could cure it in dogs with cod liver oil. In 1922, McCollum destroyed the vitamin A in cod liver oil, but found that it still cured rickets. Also in 1922, H.M. Evans and L.S. Bishop discover vitamin E as essential for rat pregnancy, originally calling it "food factor X" until 1925.
What was cod liver oil able to help cure in dogs?
The answer is the following: rickets

Problem: The FA Cup winners qualify for the following season's UEFA Europa League (formerly named the UEFA Cup; until 1998 they entered the Cup Winners' Cup instead). This European place applies even if the team is relegated or is not in the English top flight. In the past, if the FA Cup winning team also qualified for the following season's Champions League or Europa League through their league position, then the losing FA Cup finalist was given the Europa League place instead. FA Cup winners enter the Europa League at the group stage. Losing finalists, if they entered the Europa League, began earlier, at the play-off or third qualifying round stage. From the 201516 UEFA Europa League season, however, UEFA will not allow the runners-up to qualify for the Europa League through the competition.
what about the FA Cup winner?
The answer is the following: FA Cup winners enter the Europa League at the group stage.

Problem: With nearly a third of Bostonians using public transit for their commute to work, Boston has the fifth-highest rate of public transit usage in the country. Boston's subway system, the Massachusetts Bay Transportation Authority (MBTAknown as the "T") operates the oldest underground rapid transit system in the Americas, and is the fourth-busiest rapid transit system in the country, with 65.5 miles (105 km) of track on four lines. The MBTA also operates busy bus and commuter rail networks, and water shuttles.
Where does Boston rank nationally in terms of public transportation use?
The answer is the following: fifth-highest

Problem: During the Gilded Age, there was substantial growth in population in the United States and extravagant displays of wealth and excess of America's upper-class during the post-Civil War and post-Reconstruction era, in the late 19th century. The wealth polarization derived primarily from industrial and population expansion. The businessmen of the Second Industrial Revolution created industrial towns and cities in the Northeast with new factories, and contributed to the creation of an ethnically diverse industrial working class which produced the wealth owned by rising super-rich industrialists and financiers called the "robber barons". An example is the company of John D. Rockefeller, who was an important figure in shaping the new oil industry. Using highly effective tactics and aggressive practices, later widely criticized, Standard Oil absorbed or destroyed most of its competition.
In what time period did the Glided Age occur?
The answer is the following:
late 19th century