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Child labour is still common in many parts of the world. Estimates for child labour vary. It ranges between 250 and 304 million, if children aged 5–17 involved in any economic activity are counted. If light occasional work is excluded, ILO estimates there were 153 million child labourers aged 5–14 worldwide in 2008. This is about 20 million less than ILO estimate for child labourers in 2004. Some 60 percent of the child labour was involved in agricultural activities such as farming, dairy, fisheries and forestry. Another 25 percent of child labourers were in service activities such as retail, hawking goods, restaurants, load and transfer of goods, storage, picking and recycling trash, polishing shoes, domestic help, and other services. The remaining 15 percent laboured in assembly and manufacturing in informal economy, home-based enterprises, factories, mines, packaging salt, operating machinery, and such operations. Two out of three child workers work alongside their parents, in unpaid family work situations. Some children work as guides for tourists, sometimes combined with bringing in business for shops and restaurants. Child labour predominantly occurs in the rural areas (70%) and informal urban sector (26%).
Does child labour exist in the 21st century?
A: Child labour is still common

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Hydrogen gas forms explosive mixtures with air if it is 4–74% concentrated and with chlorine if it is 5–95% concentrated. The mixtures may be ignited by spark, heat or sunlight. The hydrogen autoignition temperature, the temperature of spontaneous ignition in air, is 500 °C (932 °F). Pure hydrogen-oxygen flames emit ultraviolet light and with high oxygen mix are nearly invisible to the naked eye, as illustrated by the faint plume of the Space Shuttle Main Engine compared to the highly visible plume of a Space Shuttle Solid Rocket Booster. The detection of a burning hydrogen leak may require a flame detector; such leaks can be very dangerous. Hydrogen flames in other conditions are blue, resembling blue natural gas flames. The destruction of the Hindenburg airship was an infamous example of hydrogen combustion; the cause is debated, but the visible orange flames were the result of a rich mixture of hydrogen to oxygen combined with carbon compounds from the airship skin.
What kind of light do hydrogen-oxygen flames make?
A: ultraviolet light

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Her first acting role of 2006 was in the comedy film The Pink Panther starring opposite Steve Martin, grossing $158.8 million at the box office worldwide. Her second film Dreamgirls, the film version of the 1981 Broadway musical loosely based on The Supremes, received acclaim from critics and grossed $154 million internationally. In it, she starred opposite Jennifer Hudson, Jamie Foxx, and Eddie Murphy playing a pop singer based on Diana Ross. To promote the film, Beyoncé released "Listen" as the lead single from the soundtrack album. In April 2007, Beyoncé embarked on The Beyoncé Experience, her first worldwide concert tour, visiting 97 venues and grossed over $24 million.[note 1] Beyoncé conducted pre-concert food donation drives during six major stops in conjunction with her pastor at St. John's and America's Second Harvest. At the same time, B'Day was re-released with five additional songs, including her duet with Shakira "Beautiful Liar".
How much money did Beyonce's tour make in 2007?
A: 24 million

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Ann Arbor was founded in 1824 by land speculators John Allen and Elisha Walker Rumsey. On 25 May 1824, the town plat was registered with Wayne County as "Annarbour;" this represents the earliest known use of the town's name. Allen and Rumsey decided to name it for their wives, both named Ann, and for the stands of Bur Oak in the 640 acres (260 ha) of land they purchased for $800 from the federal government at $1.25 per acre. The local Ojibwa named the settlement kaw-goosh-kaw-nick, after the sound of Allen's sawmill.
Which tribe named the settlement as kaw-goosh-kaw-nick?
A:
Ojibwa