Article: Although an alloy is technically an impure metal, when referring to alloys, the term "impurities" usually denotes those elements which are not desired. These impurities are often found in the base metals or the solutes, but they may also be introduced during the alloying process. For instance, sulfur is a common impurity in steel. Sulfur combines readily with iron to form iron sulfide, which is very brittle, creating weak spots in the steel. Lithium, sodium and calcium are common impurities in aluminium alloys, which can have adverse effects on the structural integrity of castings. Conversely, otherwise pure-metals that simply contain unwanted impurities are often called "impure metals" and are not usually referred to as alloys. Oxygen, present in the air, readily combines with most metals to form metal oxides; especially at higher temperatures encountered during alloying. Great care is often taken during the alloying process to remove excess impurities, using fluxes, chemical additives, or other methods of extractive metallurgy.

Question: What is a characteristic of iron sulfide?
Ans: very brittle


Article: Accusing the rebels of being "drugged" and linked to al-Qaeda, Gaddafi proclaimed that he would die a martyr rather than leave Libya. As he announced that the rebels would be "hunted down street by street, house by house and wardrobe by wardrobe", the army opened fire on protests in Benghazi, killing hundreds. Shocked at the government's response, a number of senior politicians resigned or defected to the protesters' side. The uprising spread quickly through Libya's less economically developed eastern half. By February's end, eastern cities like Benghazi, Misrata, al-Bayda and Tobruk were controlled by rebels, and the Benghazi-based National Transitional Council (NTC) had been founded to represent them.

Question: What rebel organization was founded in Benghazi?
Ans: National Transitional Council


Article: Tucson's largest park, Reid Park, is located in midtown and includes Reid Park Zoo and Hi Corbett Field. Speedway Boulevard, a major east-west arterial road in central Tucson, was named the "ugliest street in America" by Life magazine in the early 1970s, quoting Tucson Mayor James Corbett. Despite this, Speedway Boulevard was awarded "Street of the Year" by Arizona Highways in the late 1990s. According to David Leighton, historical writer for the Arizona Daily Star newspaper, Speedway Boulevard derives its name from an old horse racetrack, known as "The Harlem River Speedway," more commonly called "The Speedway," in New York City. The street was called "The Speedway," from 1904 to about 1906 before the word "The" was taken out.

Question: Which newspaper did David Leighton work for?
Ans: Arizona Daily Star


Article: In Canada, the Royal Newfoundland Constabulary was founded in 1729, making it the first police force in present-day Canada. It was followed in 1834 by the Toronto Police, and in 1838 by police forces in Montreal and Quebec City. A national force, the Dominion Police, was founded in 1868. Initially the Dominion Police provided security for parliament, but its responsibilities quickly grew. The famous Royal Northwest Mounted Police was founded in 1873. The merger of these two police forces in 1920 formed the world-famous Royal Canadian Mounted Police.

Question: When was the Toronto police created?
Ans:
1834