Problem: United States Army:

The American Civil War was the costliest war for the U.S. in terms of casualties. After most slave states, located in the southern U.S., formed the Confederate States, C.S. troops led by former U.S. Army officers, mobilized a very large fraction of Southern white manpower. Forces of the United States (the "Union" or "the North") formed the Union Army consisting of a small body of regular army units and a large body of volunteer units raised from every state, north and south, except South Carolina.[citation needed]

What was the least expensive war for the U.S.?
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A: unanswerable


Problem: In the Middle Ages, the site of the future palace formed part of the Manor of Ebury (also called Eia). The marshy ground was watered by the river Tyburn, which still flows below the courtyard and south wing of the palace. Where the river was fordable (at Cow Ford), the village of Eye Cross grew. Ownership of the site changed hands many times; owners included Edward the Confessor and his queen consort Edith of Wessex in late Saxon times, and, after the Norman Conquest, William the Conqueror. William gave the site to Geoffrey de Mandeville, who bequeathed it to the monks of Westminster Abbey.
What was the name of the manor that previously existed on the site?
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Answer: Manor of Ebury


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
According to the American National Standards Institute, pitch is the auditory attribute of sound according to which sounds can be ordered on a scale from low to high. Since pitch is such a close proxy for frequency, it is almost entirely determined by how quickly the sound wave is making the air vibrate and has almost nothing to do with the intensity, or amplitude, of the wave. That is, "high" pitch means very rapid oscillation, and "low" pitch corresponds to slower oscillation. Despite that, the idiom relating vertical height to sound pitch is shared by most languages. At least in English, it is just one of many deep conceptual metaphors that involve up/down. The exact etymological history of the musical sense of high and low pitch is still unclear. There is evidence that humans do actually perceive that the source of a sound is slightly higher or lower in vertical space when the sound frequency is increased or decreased.
Pitch is a close proxy for what?
A: frequency


Context and question: In contrast, procedural memory (or implicit memory) is not based on the conscious recall of information, but on implicit learning. It can best be summarized as remember how to do something. Procedural memory is primarily employed in learning motor skills and should be considered a subset of implicit memory. It is revealed when one does better in a given task due only to repetition - no new explicit memories have been formed, but one is unconsciously accessing aspects of those previous experiences. Procedural memory involved in motor learning depends on the cerebellum and basal ganglia.
What type of memory does not depend on the cerebellum and basal ganglia?
Answer: unanswerable


Question: On December 7, 1989, the Communist Party of Lithuania under the leadership of Algirdas Brazauskas, split from the Communist Party of the Soviet Union and abandoned its claim to have a constitutional "leading role" in politics. A smaller loyalist faction of the Communist Party, headed by hardliner Mykolas Burokevičius, was established and remained affiliated with the CPSU. However, Lithuania’s governing Communist Party was formally independent from Moscow's control – a first for Soviet Republics and a political earthquake that prompted Gorbachev to arrange a visit to Lithuania the following month in a futile attempt to bring the local party back under control.
Is there an answer to this question: What place's control was the Communist Party of Lithuania out from under after the split?

Answer: Moscow's


Question: Not all introduced species are invasive, nor all invasive species deliberately introduced. In cases such as the zebra mussel, invasion of US waterways was unintentional. In other cases, such as mongooses in Hawaii, the introduction is deliberate but ineffective (nocturnal rats were not vulnerable to the diurnal mongoose). In other cases, such as oil palms in Indonesia and Malaysia, the introduction produces substantial economic benefits, but the benefits are accompanied by costly unintended consequences.
Is there an answer to this question: What animals were not vulnerable to the zebra mussel?

Answer:
unanswerable