Problem: Estonia:

The architectural history of Estonia mainly reflects its contemporary development in northern Europe. Worth mentioning is especially the architectural ensemble that makes out the medieval old town of Tallinn, which is on the UNESCO World Heritage List. In addition, the country has several unique, more or less preserved hill forts dating from pre-Christian times, a large number of still intact medieval castles and churches, while the countryside is still shaped by the presence of a vast number of manor houses from earlier centuries.

When were the preserved hill forts in Estonia built?
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A: pre-Christian times

Problem: Compact disc:

Meanwhile, with the advent and popularity of Internet-based distribution of files in lossily-compressed audio formats such as MP3, sales of CDs began to decline in the 2000s. For example, between 2000 - 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%, although independent and DIY music sales may be tracking better according to figures released 30 March 2009, and CDs still continue to sell greatly. As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015.

What portion of music sales did CDs and DVDs account for in the United States as of 2012?
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A: 34 percent

Problem: Unicode:

Unicode can be implemented by different character encodings. The most commonly used encodings are UTF-8, UTF-16 and the now-obsolete UCS-2. UTF-8 uses one byte for any ASCII character, all of which have the same code values in both UTF-8 and ASCII encoding, and up to four bytes for other characters. UCS-2 uses a 16-bit code unit (two 8-bit bytes) for each character but cannot encode every character in the current Unicode standard. UTF-16 extends UCS-2, using one 16-bit unit for the characters that were representable in UCS-2 and two 16-bit units (4 8 bits) to handle each of the additional characters.

What did UCS-2 expand?
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A: unanswerable

Problem: IPod:

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."

in what year was the original iPod released?
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A:
2001