Input: Read this: In 1877, John Wanamaker opened the United State's first modern department store in a former Pennsylvania Railroad freight terminal in Philadelphia. Wanamakers was the first department store to offer fixed prices marked on every article and also introduced electrical illumination (1878), the telephone (1879), and the use of pneumatic tubes to transport cash and documents (1880) to the department store business. Subsequent department stores founded in Philadelphia included Strawbridge and Clothier, Gimbels, Lit Brothers, and Snellenbergs.
Question: How were important documents and money transported throughout the store?

Output: pneumatic tubes

Input: Read this: Laws dating from 17th-century colonial America defined children of African slave mothers as taking the status of their mothers, and born into slavery regardless of the race or status of the father, under partus sequitur ventrem. The association of slavery with a "race" led to slavery as a racial caste. But, most families of free people of color formed in Virginia before the American Revolution were the descendants of unions between white women and African men, who frequently worked and lived together in the looser conditions of the early colonial period. While interracial marriage was later prohibited, white men frequently took sexual advantage of slave women, and numerous generations of multiracial children were born. By the late 1800s it had become common among African Americans to use passing to gain educational opportunities as did the first African-American graduate of Vassar College Anita Florence Hemmings. Some 19th-century categorization schemes defined people by proportion of African ancestry: a person whose parents were black and white was classified as mulatto, with one black grandparent and three white as quadroon, and with one black great-grandparent and the remainder white as octoroon. The latter categories remained within an overall black or colored category, but before the Civil War, in Virginia and some other states, a person of one-eighth or less black ancestry was legally white. Some members of these categories passed temporarily or permanently as white.
Question: What did African Americans not use passing to do?

Output: unanswerable

Input: Read this: BBC TV was renamed BBC1 in 1964, after the launch of BBC2 (now BBC Two), the third television station (ITV was the second) for the UK; its remit, to provide more niche programming. The channel was due to launch on 20 April 1964, but was put off the air by a massive power failure that affected much of London, caused by a fire at Battersea Power Station. A videotape made on the opening night was rediscovered in 2003 by a BBC technician. In the end the launch went ahead the following night, hosted by Denis Tuohy holding a candle. BBC2 was the first British channel to use UHF and 625-line pictures, giving higher definition than the existing VHF 405-line system.
Question: What was discovered in 2003 by an ITV technician?

Output: unanswerable

Input: Read this: In June 2009, many of the world's largest mobile phone manufacturers signed an EC-sponsored Memorandum of Understanding (MoU), agreeing to make most data-enabled mobile phones marketed in the European Union compatible with a common External Power Supply (EPS). The EU's common EPS specification (EN 62684:2010) references the USB Battery Charging standard and is similar to the GSMA/OMTP and Chinese charging solutions. In January 2011, the International Electrotechnical Commission (IEC) released its version of the (EU's) common EPS standard as IEC 62684:2011.
Question: When did the IEC release its version of the common EPS standard as IEC 62684:2011?

Output:
January 2011