Problem: NARA's holdings are classed into "record groups" reflecting the governmental department or agency from which they originated. Records include paper documents, microfilm, still pictures, motion pictures, and electronic media.
What record types were used more in the past than they are now?
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Answer: unanswerable


Problem: South West Africa became known as Namibia by the UN when the General Assembly changed the territory's name by Resolution 2372 (XXII) of 12 June 1968. In 1978 the UN Security Council passed UN Resolution 435 which planned a transition toward independence for Namibia. Attempts to persuade South Africa to agree to the plan's implementation were not successful until 1988 when the transition to independence finally started under a diplomatic agreement between South Africa, Angola and Cuba, with the USSR and the USA as observers, under which South Africa agreed to withdraw and demobilise its forces in Namibia. As a result, Cuba agreed to pull back its troops in southern Angola sent to support the MPLA in its war for control of Angola with UNITA.
Since what year had UNITA controlled Angola?
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Answer: unanswerable


Problem: Data compression can be viewed as a special case of data differencing: Data differencing consists of producing a difference given a source and a target, with patching producing a target given a source and a difference, while data compression consists of producing a compressed file given a target, and decompression consists of producing a target given only a compressed file. Thus, one can consider data compression as data differencing with empty source data, the compressed file corresponding to a "difference from nothing." This is the same as considering absolute entropy (corresponding to data compression) as a special case of relative entropy (corresponding to data differencing) with no initial data.
What is made up of producing a difference given a source and a target?
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Answer:
Data differencing