Problem: Compact disc:

CD-R recordings are designed to be permanent. Over time, the dye's physical characteristics may change causing read errors and data loss until the reading device cannot recover with error correction methods. The design life is from 20 to 100 years, depending on the quality of the discs, the quality of the writing drive, and storage conditions. However, testing has demonstrated such degradation of some discs in as little as 18 months under normal storage conditions. This failure is known as disc rot, for which there are several, mostly environmental, reasons.

What type of environment is best for a CD-R?
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A: unanswerable


Problem: In South Africa, a "two apex" system existed from 1994 to 2013. The Supreme Court of Appeal (SCA) was created in 1994 and replaced the Appellate Division of the Supreme Court of South Africa as the highest court of appeal in non-constitutional matters. The SCA is subordinate to the Constitutional Court, which is the highest court in matters involving the interpretation and application of the Constitution. But in August 2013 the Constitution was amended to make the Constitutional Court the country's single apex court, superior to the SCA in all matters, both constitutional and non-constitutional.
When did the Constitutional Court become the highest court in South Africa in all matters?
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Answer: August 2013


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The monastic communities of the Judean Desert also decorated their monasteries with mosaic floors. The Monastery of Martyrius was founded in the end of the 5th century and it was re-discovered in 1982–85. The most important work of art here is the intact geometric mosaic floor of the refectory although the severely damaged church floor was similarly rich. The mosaics in the church of the nearby Monastery of Euthymius are of later date (discovered in 1930). They were laid down in the Umayyad era, after a devastating earthquake in 659. Two six pointed stars and a red chalice are the most important surviving features.
When was the Monastery of Martyrius created?
A: the end of the 5th century


Context and question: Due to the ratio of U.S. and Mexican-licensed stations, San Diego is the largest media market in the United States that is legally unable to support a television station duopoly between two full-power stations under FCC regulations, which disallow duopolies in metropolitan areas with fewer than nine full-power television stations and require that there must be eight unique station owners that remain once a duopoly is formed (there are only seven full-power stations on the California side of the San Diego-Tijuana market).[citation needed] Though the E. W. Scripps Company owns KGTV and KZSD-LP, they are not considered a duopoly under the FCC's legal definition as common ownership between full-power and low-power television stations in the same market is permitted regardless to the number of stations licensed to the area. As a whole, the Mexico side of the San Diego-Tijuana market has two duopolies and one triopoly (Entravision Communications owns both XHAS-TV and XHDTV-TV, Azteca owns XHJK-TV and XHTIT-TV, and Grupo Televisa owns XHUAA-TV and XHWT-TV along with being the license holder for XETV-TV, which is run by California-based subsidiary Bay City Television).
What company disowns XHDTV-TV and XHAS-TV?
Answer: unanswerable


Question: Mexico City, being the seat of the powers of the Union, did not belong to any particular state but to all. Therefore, it was the president, representing the federation, who used to designate the head of government of the Federal District, a position which is sometimes presented outside Mexico as the "Mayor" of Mexico City.[citation needed] In the 1980s, given the dramatic increase in population of the previous decades, the inherent political inconsistencies of the system, as well as the dissatisfaction with the inadequate response of the federal government after the 1985 earthquake, residents began to request political and administrative autonomy to manage their local affairs.[citation needed] Some political groups even proposed that the Federal District be converted into the 32nd state of the federation.
Is there an answer to this question: What do people call the leader of Mexico City?

Answer: Mayor


Problem: Law of the United States:

During the 18th and 19th centuries, federal law traditionally focused on areas where there was an express grant of power to the federal government in the federal Constitution, like the military, money, foreign relations (especially international treaties), tariffs, intellectual property (specifically patents and copyrights), and mail. Since the start of the 20th century, broad interpretations of the Commerce and Spending Clauses of the Constitution have enabled federal law to expand into areas like aviation, telecommunications, railroads, pharmaceuticals, antitrust, and trademarks. In some areas, like aviation and railroads, the federal government has developed a comprehensive scheme that preempts virtually all state law, while in others, like family law, a relatively small number of federal statutes (generally covering interstate and international situations) interacts with a much larger body of state law. In areas like antitrust, trademark, and employment law, there are powerful laws at both the federal and state levels that coexist with each other. In a handful of areas like insurance, Congress has enacted laws expressly refusing to regulate them as long as the states have laws regulating them (see, e.g., the McCarran-Ferguson Act).

When did the Commerce and Spending Clauses of the Constitution allow federal power to begin expanding?
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A:
start of the 20th century