Problem: Muslim world:

The two main denominations of Islam are the Sunni and Shia sects. They differ primarily upon of how the life of the ummah ("faithful") should be governed, and the role of the imam. These two main differences stem from the understanding of which hadith are to interpret the Quran. Sunnis believe the true political successor of the Prophet in Sunnah is based on Shura (consultation) at the Saqifah which selected Abu Bakr, father of the Prophet's favourite wife, 'A'ishah, to lead the Islamic community while the religious succession ceased to exist on account of finality of Prophethood. Shia on the other hand believe that the true political as well as religious successor is Ali ibn Abi Talib, husband of the Prophet's daughter Fatimah (designated by the Prophet).

What type of sucessor do the Shia believe Abu Bakr was?
---
A: unanswerable

Problem: Nanjing is endowed with rich natural resources, which include more than 40 kinds of minerals. Among them, iron and sulfur reserves make up 40 percent of those of Jiangsu province. Its reserves of strontium rank first in East Asia and the South East Asia region. Nanjing also possesses abundant water resources, both from the Yangtze River and groundwater. In addition, it has several natural hot springs such as Tangshan Hot Spring in Jiangning and Tangquan Hot Spring in Pukou.
How many types of minerals are found in Nanjing?
---
Answer: 40

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Beginning in April 1985, Madonna embarked on her first concert tour in North America, The Virgin Tour, with the Beastie Boys as her opening act. She progressed from playing CBGB and the Mudd Club to playing large sporting arenas. At that time she released two more hit singles from the album, "Angel" and "Dress You Up". In July, Penthouse and Playboy magazines published a number of nude photos of Madonna, taken in New York in 1978. She had posed for the photographs as she needed money at the time, and was paid as little as $25 a session. The publication of the photos caused a media uproar, but Madonna remained "unapologetic and defiant". The photographs were ultimately sold for up to $100,000. She referred to these events at the 1985 outdoor Live Aid charity concert, saying that she would not take her jacket off because "[the media] might hold it against me ten years from now."
When was Madonna's first concert tour in North America?
A: Beginning in April 1985

Context and question: The Human Development Index has been criticized on a number of grounds including alleged ideological biases towards egalitarianism and so-called "Western models of development", failure to include any ecological considerations, lack of consideration of technological development or contributions to the human civilization, focusing exclusively on national performance and ranking, lack of attention to development from a global perspective, measurement error of the underlying statistics, and on the UNDP's changes in formula which can lead to severe misclassification in the categorisation of 'low', 'medium', 'high' or 'very high' human development countries.
Has the HDI been criticized for being biased towards Northern or towards Southern models of development?
Answer: unanswerable

Question: By March 2011, the market share of OS X in North America had increased to slightly over 14%. Whether the size of the Mac's market share and installed base is relevant, and to whom, is a hotly debated issue. Industry pundits have often called attention to the Mac's relatively small market share to predict Apple's impending doom, particularly in the early and mid-1990s when the company's future seemed bleakest. Others argue that market share is the wrong way to judge the Mac's success. Apple has positioned the Mac as a higher-end personal computer, and so it may be misleading to compare it to a budget PC. Because the overall market for personal computers has grown rapidly, the Mac's increasing sales numbers are effectively swamped by the industry's expanding sales volume as a whole. Apple's small market share, then, gives the impression that fewer people are using Macs than did ten years ago, when exactly the opposite is true. Soaring sales of the iPhone and iPad mean that the portion of Apple's profits represented by the Macintosh has declined in 2010, dropping to 24% from 46% two years earlier. Others try to de-emphasize market share, citing that it is rarely brought up in other industries. Regardless of the Mac's market share, Apple has remained profitable since Steve Jobs' return and the company's subsequent reorganization. Notably, a report published in the first quarter of 2008 found that Apple had a 14% market share in the personal computer market in the US, including 66% of all computers over $1,000. Market research indicates that Apple draws its customer base from a higher-income demographic than the mainstream personal computer market.
Is there an answer to this question: According to market research, who does Microsoft draw it's customer base from?

Answer: unanswerable

Problem: Tristan da Cunha:

During World War II, the islands were used as a top secret Royal Navy weather and radio station codenamed HMS Atlantic Isle, to monitor Nazi U-boats (which were required to maintain radio contact) and shipping movements in the South Atlantic Ocean. The first Administrator, Surgeon Lieutenant Commander E.J.S. Woolley, was appointed by the British government during this time.

What were the islands used as during World War I?
---
A:
unanswerable