Problem: Roman Republic:

The first few naval battles were disasters for Rome. However, after training more sailors and inventing a grappling engine, a Roman naval force was able to defeat a Carthaginian fleet, and further naval victories followed. The Carthaginians then hired Xanthippus of Carthage, a Spartan mercenary general, to reorganise and lead their army. He cut off the Roman army from its base by re-establishing Carthaginian naval supremacy. The Romans then again defeated the Carthaginians in naval battle at the Battle of the Aegates Islands and left Carthage with neither a fleet nor sufficient coin to raise one. For a maritime power the loss of their access to the Mediterranean stung financially and psychologically, and the Carthaginians sued for peace.

Who did the Carthaginians hire to lead their army after several losses against the Romans?
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A: Xanthippus

Problem: In 1958 as part of an experiment, Operation Argus, the United States Navy detonated an atomic bomb 160 kilometres (100 mi) high in the upper atmosphere about 175 kilometres (109 mi) southeast of the main island.
During which mission did the US Army detonate an atomic bomb?
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Answer: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Nigeria is home to a substantial network of organised crime, active especially in drug trafficking. Nigerian criminal groups are heavily involved in drug trafficking, shipping heroin from Asian countries to Europe and America; and cocaine from South America to Europe and South Africa. . The various Nigerian Confraternities or "campus cults" are active in both organised crime and in political violence as well as providing a network of corruption within Nigeria. As confraternities have extensive connections with political and military figures, they offer excellent alumni networking opportunities. The Supreme Vikings Confraternity, for example, boasts that twelve members of the Rivers State House of Assembly are cult members. On lower levels of society, there are the "area boys", organised gangs mostly active in Lagos who specialise in mugging and small-scale drug dealing. According to official statistics, gang violence in Lagos resulted in 273 civilians and 84 policemen killed in the period of August 2000 to May 2001.
What drug does Nigeria ship from Asia to Europe and America?
A: heroin

Context and question: Carnivore was an electronic eavesdropping software system implemented by the FBI during the Clinton administration; it was designed to monitor email and electronic communications. After prolonged negative coverage in the press, the FBI changed the name of its system from "Carnivore" to "DCS1000." DCS is reported to stand for "Digital Collection System"; the system has the same functions as before. The Associated Press reported in mid-January 2005 that the FBI essentially abandoned the use of Carnivore in 2001, in favor of commercially available software, such as NarusInsight.
When did the FBI abandon Carnivore?
Answer: 2001

Question: Of major Canadian cities, St. John's is the foggiest (124 days), windiest (24.3 km/h (15.1 mph) average speed), and cloudiest (1,497 hours of sunshine). St. John's experiences milder temperatures during the winter season in comparison to other Canadian cities, and has the mildest winter for any Canadian city outside of British Columbia. Precipitation is frequent and often heavy, falling year round. On average, summer is the driest season, with only occasional thunderstorm activity, and the wettest months are from October to January, with December the wettest single month, with nearly 165 millimetres of precipitation on average. This winter precipitation maximum is quite unusual for humid continental climates, which most commonly have a late spring or early summer precipitation maximum (for example, most of the Midwestern U.S.). Most heavy precipitation events in St. John's are the product of intense mid-latitude storms migrating from the Northeastern U.S. and New England states, and these are most common and intense from October to March, bringing heavy precipitation (commonly 4 to 8 centimetres of rainfall equivalent in a single storm), and strong winds. In winter, two or more types of precipitation (rain, freezing rain, sleet and snow) can fall from passage of a single storm. Snowfall is heavy, averaging nearly 335 centimetres per winter season. However, winter storms can bring changing precipitation types. Heavy snow can transition to heavy rain, melting the snow cover, and possibly back to snow or ice (perhaps briefly) all in the same storm, resulting in little or no net snow accumulation. Snow cover in St. John's is variable, and especially early in the winter season, may be slow to develop, but can extend deeply into the spring months (March, April). The St. John's area is subject to freezing rain (called "silver thaws"), the worst of which paralyzed the city over a three-day period in April 1984.
Is there an answer to this question: What is the driest season on average in St. John's?

Answer: summer

Question: In psychology, memory is the process in which information is encoded, stored, and retrieved. Encoding allows information from the outside world to be sensed in the form of chemical and physical stimuli. In the first stage the information must be changed so that it may be put into the encoding process. Storage is the second memory stage or process. This entails that information is maintained over short periods of time. Finally the third process is the retrieval of information that has been stored. Such information must be located and returned to the consciousness. Some retrieval attempts may be effortless due to the type of information, and other attempts to remember stored information may be more demanding for various reasons.
Is there an answer to this question: What is the fourth memory stage?

Answer:
unanswerable