This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
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Question: Karlheinz Brandenburg used a CD recording of Suzanne Vega's song "Tom's Diner" to assess and refine the MP3 compression algorithm. This song was chosen because of its nearly monophonic nature and wide spectral content, making it easier to hear imperfections in the compression format during playbacks. Some refer to Suzanne Vega as "The mother of MP3". This particular track has an interesting property in that the two channels are almost, but not completely, the same, leading to a case where Binaural Masking Level Depression causes spatial unmasking of noise artifacts unless the encoder properly recognizes the situation and applies corrections similar to those detailed in the MPEG-2 AAC psychoacoustic model. Some more critical audio excerpts (glockenspiel, triangle, accordion, etc.) were taken from the EBU V3/SQAM reference compact disc and have been used by professional sound engineers to assess the subjective quality of the MPEG Audio formats.

Answer: What type of recording did Brandenburg use?


Question: Events in America influenced British policy in Canada, where between 40,000 and 100,000 defeated Loyalists had migrated from America following independence. The 14,000 Loyalists who went to the Saint John and Saint Croix river valleys, then part of Nova Scotia, felt too far removed from the provincial government in Halifax, so London split off New Brunswick as a separate colony in 1784. The Constitutional Act of 1791 created the provinces of Upper Canada (mainly English-speaking) and Lower Canada (mainly French-speaking) to defuse tensions between the French and British communities, and implemented governmental systems similar to those employed in Britain, with the intention of asserting imperial authority and not allowing the sort of popular control of government that was perceived to have led to the American Revolution.

Answer: How many British loyalists moved from the US to Canada?


Question: At Maecenas' insistence (according to the tradition) Virgil spent the ensuing years (perhaps 37–29 BC) on the long didactic hexameter poem called the Georgics (from Greek, "On Working the Earth") which he dedicated to Maecenas. The ostensible theme of the Georgics is instruction in the methods of running a farm. In handling this theme, Virgil follows in the didactic ("how to") tradition of the Greek poet Hesiod's Works and Days and several works of the later Hellenistic poets. The four books of the Georgics focus respectively on raising crops and trees (1 and 2), livestock and horses (3), and beekeeping and the qualities of bees (4). Well-known passages include the beloved Laus Italiae of Book 2, the prologue description of the temple in Book 3, and the description of the plague at the end of Book 3. Book 4 concludes with a long mythological narrative, in the form of an epyllion which describes vividly the discovery of beekeeping by Aristaeus and the story of Orpheus' journey to the underworld. Ancient scholars, such as Servius, conjectured that the Aristaeus episode replaced, at the emperor's request, a long section in praise of Virgil's friend, the poet Gallus, who was disgraced by Augustus, and who committed suicide in 26 BC.

Answer:
Which long didactic hexameter poem did Virgil work on for several years?