Problem: Nigeria:

Everything in between the far south and the far north is savannah (insignificant tree cover, with grasses and flowers located between trees). Rainfall is more limited, to between 500 and 1,500 millimetres (20 and 60 in) per year. The savannah zone's three categories are Guinean forest-savanna mosaic, Sudan savannah, and Sahel savannah. Guinean forest-savanna mosaic is plains of tall grass interrupted by trees. Sudan savannah is similar but with shorter grasses and shorter trees. Sahel savannah consists of patches of grass and sand, found in the northeast. In the Sahel region, rain is less than 500 millimetres (20 in) per year and the Sahara Desert is encroaching. In the dry north-east corner of the country lies Lake Chad, which Nigeria shares with Niger, Chad and Cameroon.

How much rain does the Sahel savannah area get per year?
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A: less than 500 millimetres (20 in)


Problem: Samoa:

Rugby league is mostly played by Samoans living in New Zealand and Australia,[citation needed] with Samoa reaching the quarter finals of the 2013 Rugby League World Cup made of players playing in the NRL, Super League and domestic players. Many Samoans and New Zealanders or Australians of Samoan descent play in the Super League and National Leagues in Britain. Francis Meli, Ta'ane Lavulavu of Workington Town, Maurie Fa'asavalu of St Helens and David Fatialofa of Whitehaven and Setima Sa who signed with London Irish rugby club. Other noteworthy players from NZ and Australia have represented the Samoan National team. The 2011 domestic Samoan rugby league competition contained 10 teams with plans to expand to 12 in 2012.

How many teams played in the 2011 domestic Samoan rugby league competition?
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A: 10


Problem: Bras%C3%ADlia:

Brasília is known as a departing point for the practice of unpowered air sports, sports that may be practiced with hang gliding or paragliding wings. Practitioners of such sports reveal that, because of the city's dry weather, the city offers strong thermal winds and great "cloud-streets", which is also the name for a manoeuvre quite appreciated by practitioners. In 2003, Brasília hosted the 14th Hang Gliding World Championship, one of the categories of free flying. In August 2005, the city hosted the 2nd stage of the Brazilian Hang Gliding Championship.

What is thermal wind known as?
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A: unanswerable


Problem: MP3:

A more sophisticated MP3 encoder can produce variable bitrate audio. MPEG audio may use bitrate switching on a per-frame basis, but only layer III decoders must support it. VBR is used when the goal is to achieve a fixed level of quality. The final file size of a VBR encoding is less predictable than with constant bitrate. Average bitrate is VBR implemented as a compromise between the two: the bitrate is allowed to vary for more consistent quality, but is controlled to remain near an average value chosen by the user, for predictable file sizes. Although an MP3 decoder must support VBR to be standards compliant, historically some decoders have bugs with VBR decoding, particularly before VBR encoders became widespread.

Using VBR instead of a constant bit rate encoding makes which part of encoding less predictable?
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A:
final file size