Question: At the time the store was introduced, purchased audio files used the AAC format with added encryption, based on the FairPlay DRM system. Up to five authorized computers and an unlimited number of iPods could play the files. Burning the files with iTunes as an audio CD, then re-importing would create music files without the DRM. The DRM could also be removed using third-party software. However, in a deal with Apple, EMI began selling DRM-free, higher-quality songs on the iTunes Stores, in a category called "iTunes Plus." While individual songs were made available at a cost of US$1.29, 30¢ more than the cost of a regular DRM song, entire albums were available for the same price, US$9.99, as DRM encoded albums. On October 17, 2007, Apple lowered the cost of individual iTunes Plus songs to US$0.99 per song, the same as DRM encoded tracks. On January 6, 2009, Apple announced that DRM has been removed from 80% of the music catalog, and that it would be removed from all music by April 2009.
Is there an answer to this question: How many computers were allowed to play files that used the FairPlay DRM system?

Answer: five


Question: For several decades, peace reigned in Tibet, but in 1792 the Qing Qianlong Emperor sent a large Chinese army into Tibet to push the invading Nepalese out. This prompted yet another Qing reorganization of the Tibetan government, this time through a written plan called the "Twenty-Nine Regulations for Better Government in Tibet". Qing military garrisons staffed with Qing troops were now also established near the Nepalese border. Tibet was dominated by the Manchus in various stages in the 18th century, and the years immediately following the 1792 regulations were the peak of the Qing imperial commissioners' authority; but there was no attempt to make Tibet a Chinese province.
Is there an answer to this question: What year was the attempt to make Tibet a Chinese province?

Answer: unanswerable


Question: Since the 1980s it has become common for social and cultural anthropologists to set ethnographic research in the North Atlantic region, frequently examining the connections between locations rather than limiting research to a single locale. There has also been a related shift toward broadening the focus beyond the daily life of ordinary people; increasingly, research is set in settings such as scientific laboratories, social movements, governmental and nongovernmental organizations and businesses.
Is there an answer to this question: Setting research in the North Atlantic region allows looking at connections between locations rather than being limited to what?

Answer: research to a single locale


Question: The term mainly refers to a mix of lithium and aluminosilicates that yields an array of materials with interesting thermomechanical properties. The most commercially important of these have the distinction of being impervious to thermal shock. Thus, glass-ceramics have become extremely useful for countertop cooking. The negative thermal expansion coefficient (CTE) of the crystalline ceramic phase can be balanced with the positive CTE of the glassy phase. At a certain point (~70% crystalline) the glass-ceramic has a net CTE near zero. This type of glass-ceramic exhibits excellent mechanical properties and can sustain repeated and quick temperature changes up to 1000 °C.
Is there an answer to this question: What proportion of crystalline ceramics yields a product with a CTE of around 0?

Answer:
~70%