Problem: Tucson, Arizona:

Tucson's Sun Tran bus system serves greater Tucson with standard, express, regional shuttle, and on-demand shuttle bus service. It was awarded Best Transit System in 1988 and 2005. A 3.9-mile streetcar line, Sun Link, connects the University of Arizona campus with 4th Avenue, downtown, and the Mercado District west of Interstate 10 and the Santa Cruz River. Ten-minute headway passenger service began July 25, 2014. The streetcar utilizes Sun Tran's card payment and transfer system, connecting with the University of Arizona's CatTran shuttles, Amtrak, and Greyhound intercity bus service.

What is Tucson's bus system called?
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A: Sun Tran


Problem: Though the iPod was released in 2001, its price and Mac-only compatibility caused sales to be relatively slow until 2004. The iPod line came from Apple's "digital hub" category, when the company began creating software for the growing market of personal digital devices. Digital cameras, camcorders and organizers had well-established mainstream markets, but the company found existing digital music players "big and clunky or small and useless" with user interfaces that were "unbelievably awful," so Apple decided to develop its own. As ordered by CEO Steve Jobs, Apple's hardware engineering chief Jon Rubinstein assembled a team of engineers to design the iPod line, including hardware engineers Tony Fadell and Michael Dhuey, and design engineer Sir Jonathan Ive. Rubinstein had already discovered the Toshiba disk drive when meeting with an Apple supplier in Japan, and purchased the rights to it for Apple, and had also already worked out how the screen, battery, and other key elements would work. The aesthetic was inspired by the 1958 Braun T3 transistor radio designed by Dieter Rams, while the wheel based user interface was prompted by Bang & Olufsen's BeoCom 6000 telephone. The product ("the Walkman of the twenty-first century" ) was developed in less than one year and unveiled on October 23, 2001. Jobs announced it as a Mac-compatible product with a 5 GB hard drive that put "1,000 songs in your pocket."
What is the name of Apple's hardware engineering chief who helped design the iPod?
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Answer: Jon Rubinstein


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Modern Ottoman studies think that the change in relations between the Ottoman Turks and central Europe was caused by the opening of the new sea routes. It is possible to see the decline in the significance of the land routes to the East as Western Europe opened the ocean routes that bypassed the Middle East and Mediterranean as parallel to the decline of the Ottoman Empire itself. The Anglo-Ottoman Treaty, also known as the Treaty of Balta Liman that opened the Ottoman markets directly to English and French competitors, would be seen as one of the staging posts along this development.
In what direction did land routes lose their importance?
A: East


Context and question: Hunting and gathering was presumably the subsistence strategy employed by human societies beginning some 1.8 million years ago, by Homo erectus, and from its appearance some 0.2 million years ago by Homo sapiens. It remained the only mode of subsistence until the end of the Mesolithic period some 10,000 years ago, and after this was replaced only gradually with the spread of the Neolithic Revolution.
What was replaced only gradually with the spread of the Mesolithic Revolution?
Answer: unanswerable


Question: Economic sanctions against Iran, such as the embargo against Iranian crude oil, have affected the economy. Sanctions have led to a steep fall in the value of the rial, and as of April 2013 one US dollar is worth 36,000 rial, compared with 16,000 in early 2012. Following a successful implementation of the 2015 nuclear and sanctions relief deal, the resulting benefits might not be distributed evenly across the Iranian economy as political elites such as the Islamic Revolutionary Guard Corps have garnered more resources and economic interests.
Is there an answer to this question: How much was 1 US Dollar worth in Iranian Rials in April 2013?

Answer: 36,000


Problem: Korean War:

On 25 November at the Korean western front, the PVA 13th Army Group attacked and overran the ROK II Corps at the Battle of the Ch'ongch'on River, and then decimated the US 2nd Infantry Division on the UN forces' right flank. The UN Command retreated; the U.S. Eighth Army's retreat (the longest in US Army history) was made possible because of the Turkish Brigade's successful, but very costly, rear-guard delaying action near Kunuri that slowed the PVA attack for two days (27–29 November). On 27 November at the Korean eastern front, a U.S. 7th Infantry Division Regimental Combat Team (3,000 soldiers) and the U.S. 1st Marine Division (12,000–15,000 marines) were unprepared for the PVA 9th Army Group's three-pronged encirclement tactics at the Battle of Chosin Reservoir, but they managed to escape under Air Force and X Corps support fire—albeit with some 15,000 collective casualties.

Whose actions helped the Eighth Army be able to retreat?
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A:
Turkish Brigade