Problem: Anti-aircraft warfare:

A plethora of anti-aircraft gun systems of smaller calibre were available to the German Wehrmacht combined forces, and among them the 1940-origin Flakvierling quadruple-20 mm-gun antiaircraft weapon system was one of the most often-seen weapons, seeing service on both land and sea. The similar Allied smaller-calibre air-defence weapons systems of the American forces were also quite capable, although they receive little attention. Their needs could cogently be met with smaller-calibre ordnance beyond using the usual singly-mounted M2 .50 caliber machine gun atop a tank's turret, as four of the ground-used "heavy barrel" (M2HB) guns were mounted together on the American Maxson firm's M45 Quadmount weapons system (as a direct answer to the Flakvierling),which were often mounted on the back of a half-track to form the Half Track, M16 GMC, Anti-Aircraft. Although of less power than Germany's 20 mm systems, the typical 4 or 5 combat batteries of an Army AAA battalion were often spread many kilometers apart from each other, rapidly attaching and detaching to larger ground combat units to provide welcome defence from enemy aircraft.

What was one of the most often seen weapons that was used both on land and sea?
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A: 1940-origin Flakvierling quadruple-20 mm-gun antiaircraft weapon system


Problem: Although Foo Fighters continued to be one of the most successful rock acts, with albums like In Your Honor (2005) reaching number two in the US and UK, many of the first wave of post-grunge bands began to fade in popularity. Acts like Creed, Staind, Puddle of Mudd and Nickelback took the genre into the 2000s with considerable commercial success, abandoning most of the angst and anger of the original movement for more conventional anthems, narratives and romantic songs. They were followed in this vein by new acts including Shinedown and Seether. Acts with more conventional hard rock sounds included Andrew W.K., Beautiful Creatures and Buckcherry, whose breakthrough album 15 (2006) went platinum and spawned the single "Sorry" (2007), which made the Top 10 of the Billboard 100. These were joined by bands with hard rock leanings that emerged in the mid-2000s from the garage rock or post punk revival, including Black Rebel Motorcycle Club and Kings of Leon, and Queens of the Stone Age from the US, Three Days Grace from Canada, Jet from Australia and The Datsuns from New Zealand. In 2009 Them Crooked Vultures, a supergroup that brought together Foo Fighters' Dave Grohl, Queens of the Stone Age's Josh Homme and Led Zeppelin bass player John Paul Jones attracted attention as a live act and released a self-titled debut album that reached the top 20 in the US and UK and the top ten in several other countries.
Three Days Grace is from what country?
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Answer: Canada


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Pressing the sheet removes the water by force; once the water is forced from the sheet, a special kind of felt, which is not to be confused with the traditional one, is used to collect the water; whereas when making paper by hand, a blotter sheet is used instead.
How is a special kind of felt removed from the sheet?
A: unanswerable


Context and question: In Latin, on the other hand, the [First name] Cardinal [Surname] order is used in the proclamation of the election of a new pope by the cardinal protodeacon: "Annuntio vobis gaudium magnum; habemus Papam: Eminentissimum ac Reverendissimum Dominum, Dominum (first name) Sanctae Romanae Ecclesiae Cardinalem (last name), ..." (Meaning: "I announce to you a great joy; we have a Pope: The Most Eminent and Most Reverend Lord, Lord (first name) Cardinal of the Holy Roman Church (last name), ...") This assumes that the new pope had been a cardinal just before becoming pope; the most recent election of a non-cardinal as pope was in 1378.
What way is used to announce the election of a new pope in Latin?
Answer: [First name] Cardinal [Surname]


Question: In the 19th century, southern and central European sport hunters often pursued game only for a trophy, usually the head or pelt of an animal, which was then displayed as a sign of prowess. The rest of the animal was typically discarded. Some cultures, however, disapprove of such waste. In Nordic countries, hunting for trophies was—and still is—frowned upon. Hunting in North America in the 19th century was done primarily as a way to supplement food supplies, although it is now undertaken mainly for sport.[citation needed] The safari method of hunting was a development of sport hunting that saw elaborate travel in Africa, India and other places in pursuit of trophies. In modern times, trophy hunting persists and is a significant industry in some areas.[citation needed]
Is there an answer to this question: What was the only goal for many European sport hunters in the 19th century?

Answer: a trophy


Question: Nigeria was ranked 30th in the world in terms of GDP (PPP) in 2012. Nigeria is the United States' largest trading partner in sub-Saharan Africa and supplies a fifth of its oil (11% of oil imports). It has the seventh-largest trade surplus with the US of any country worldwide. Nigeria is the 50th-largest export market for US goods and the 14th-largest exporter of goods to the US. The United States is the country's largest foreign investor. The International Monetary Fund (IMF) projected economic growth of 9% in 2008 and 8.3% in 2009. The IMF further projects an 8% growth in the Nigerian economy in 2011.
Is there an answer to this question: Which sub-Saharan African nation does the most trade with the US?

Answer:
Nigeria