Article: Many minerals provide pigments which have been used in green paints and dyes over the centuries. Pigments, in this case, are minerals which reflect the color green, rather that emitting it through luminescent or phosphorescent qualities. The large number of green pigments makes it impossible to mention them all. Among the more notable green minerals, however is the emerald, which is colored green by trace amounts of chromium and sometimes vanadium. Chromium(III) oxide (Cr2O3), is called chrome green, also called viridian or institutional green when used as a pigment. For many years, the source of amazonite's color was a mystery. Widely thought to have been due to copper because copper compounds often have blue and green colors, the blue-green color is likely to be derived from small quantities of lead and water in the feldspar. Copper is the source of the green color in malachite pigments, chemically known as basic copper(II) carbonate.

Question: What is the main chemical that causes emeralds to be green?
Ans: chromium

Article: On 23 October 1954 only nine years after Allies (UK, USA and USSR) defeated Nazi Germany ending World War II in Europe the admission of the Federal Republic of Germany to the North Atlantic Pact was finally decided. The incorporation of West Germany into the organization on 9 May 1955 was described as "a decisive turning point in the history of our continent" by Halvard Lange, Foreign Affairs Minister of Norway at the time. In November 1954, the USSR requested a new European Security Treaty, in order to make a final attempt to not have a remilitarized West Germany potentially opposed to the Soviet Union, with no success.

Question: Halvard Lange was a minister of which NATO member?
Ans: Norway

Article: Napoleon institutionalised plunder of conquered territories: French museums contain art stolen by Napoleon's forces from across Europe. Artefacts were brought to the Musee du Louvre for a grand central museum; his example would later serve as inspiration for more notorious imitators. He was compared to Adolf Hitler most famously by the historian Pieter Geyl in 1947 and Claude Ribbe in 2005. David G. Chandler, a foremost historian of Napoleonic warfare, wrote in 1973 that, "Nothing could be more degrading to the former [Napoleon] and more flattering to the latter [Hitler]. The comparison is odious. On the whole Napoleon was inspired by a noble dream, wholly dissimilar from Hitler's... Napoleon left great and lasting testimonies to his geniusin codes of law and national identities which survive to the present day. Adolf Hitler left nothing but destruction."

Question: In 1973, which historian objected to comparisons between Napoleon and Hitler?
Ans: David G. Chandler

Article: Samba Schools are large, social entities with thousands of members and a theme for their song and parade each year. In Rio Carnival, samba schoolsparade in the Sambadrome ("sambodromo" in Portuguese). Some of the most famous include GRES Estacao Primeira de Mangueira, GRES Portela, GRES Imperatriz Leopoldinense, GRES Beija-Flor de Nilopolis, GRES Mocidade Independente de Padre Miguel, and recently, Unidos da Tijuca and GRES Uniao da Ilha do Governador. Local tourists pay $500950, depending on the costume, to buy a Samba costume and dance in the parade. Blocos are small informal groups with a definite theme in their samba, usually satirizing the political situation. About 30 schools in Rio gather hundreds of thousands of participants. More than 440 blocos operate in Rio. Bandas are samba musical bands, also called "street carnival bands", usually formed within a single neighborhood or musical back-ground. The Carnival industry chain amassed in 2012 almost US$1 billion in revenues.

Question: How much money in US dollars did the Carnival industry make in 2012?
Ans:
1 billion