Problem: Compact disc:

As a result, in 1979, Sony and Philips set up a joint task force of engineers to design a new digital audio disc. Led by engineers Kees Schouhamer Immink and Toshitada Doi, the research pushed forward laser and optical disc technology. After a year of experimentation and discussion, the task force produced the Red Book CD-DA standard. First published in 1980, the standard was formally adopted by the IEC as an international standard in 1987, with various amendments becoming part of the standard in 1996.

In what year did Sony and Philips band together to design a new digital audio disc?
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A: 1979


Problem: Other sources include fortified food and dietary supplements, which come in various forms. A 1998 review concluded that zinc oxide, one of the most common supplements in the United States, and zinc carbonate are nearly insoluble and poorly absorbed in the body. This review cited studies which found low plasma zinc concentrations after zinc oxide and zinc carbonate were consumed compared with those seen after consumption of zinc acetate and sulfate salts. However, harmful excessive supplementation is a problem among the relatively affluent, and should probably not exceed 20 mg/day in healthy people, although the U.S. National Research Council set a Tolerable Upper Intake of 40 mg/day.
What is the only common supplement in the US?
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Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Most modern air defence systems are fairly mobile. Even the larger systems tend to be mounted on trailers and are designed to be fairly quickly broken down or set up. In the past, this was not always the case. Early missile systems were cumbersome and required much infrastructure; many could not be moved at all. With the diversification of air defence there has been much more emphasis on mobility. Most modern systems are usually either self-propelled (i.e. guns or missiles are mounted on a truck or tracked chassis) or easily towed. Even systems that consist of many components (transporter/erector/launchers, radars, command posts etc.) benefit from being mounted on a fleet of vehicles. In general, a fixed system can be identified, attacked and destroyed whereas a mobile system can show up in places where it is not expected. Soviet systems especially concentrate on mobility, after the lessons learnt in the Vietnam war between the USA and Vietnam. For more information on this part of the conflict, see SA-2 Guideline.
A mobile weapons system is likely to pop up where?
A: places where it is not expected


Context and question: Transport in the Republic of the Congo includes land, air and water transportation. The country's rail system was built by forced laborers during the 1930s and largely remains in operation. There are also over 1000 km of paved roads and two major international airports (Maya-Maya Airport and Pointe Noire Airport) which have flights to Paris and many African cities. The country also has a large port on the Atlantic Ocean at Pointe-Noire and others along the Congo River at Brazzaville and Impfondo.
When was the Congo's train system built?
Answer: 1930s


Question: In the late 13th and early 14th centuries, a process took place – primarily in Italy but partly also in the Empire – that historians have termed a 'commercial revolution'. Among the innovations of the period were new forms of partnership and the issuing of insurance, both of which contributed to reducing the risk of commercial ventures; the bill of exchange and other forms of credit that circumvented the canonical laws for gentiles against usury, and eliminated the dangers of carrying bullion; and new forms of accounting, in particular double-entry bookkeeping, which allowed for better oversight and accuracy.
Is there an answer to this question: What old form of accounting was created during the late 13th and early 14th centuries?

Answer: unanswerable


QUES: Rendering software which cannot process a Unicode character appropriately often displays it as an open rectangle, or the Unicode "replacement character" (U+FFFD, �), to indicate the position of the unrecognized character. Some systems have made attempts to provide more information about such characters. The Apple's Last Resort font will display a substitute glyph indicating the Unicode range of the character, and the SIL International's Unicode Fallback font will display a box showing the hexadecimal scalar value of the character.

What is the glyph that Apple's Last Resort font displays?
What is the answer?
ANS:
unanswerable