Input: Read this: The Canadian Rangers, who provide surveillance and patrol services in Canada's arctic and other remote areas, are an essential reserve force component used for Canada's exercise of sovereignty over its northern territory.
Question: What do the Canadian Rangers safekeep?

Output: Canada's exercise of sovereignty over its northern territory


Input: Read this: Beginning with the Paris Exposition of 1878, the instrument's popularity rebounded. The Exposition was one of many stops for a popular new performing group the Estudiantes Españoles (Spanish Students). They danced and played guitars, violins and the bandurria, which became confused with the mandolin. Along with the energy and awareness created by the day's hit sensation, a wave of Italian mandolinists travelled Europe in the 1880s and 1890s and in the United States by the mid-1880s, playing and teaching their instrument. The instrument's popularity continued to increase during the 1890s and mandolin popularity was at its height in "early years of the 20th century." Thousands were taking up the instrument as a pastime, and it became an instrument of society, taken up by young men and women. Mandolin orchestras were formed worldwide, incorporating not only the mandolin family of instruments, but also guitars, double basses and zithers.
Question: What group of people traveled to the United States in 1880?

Output: unanswerable


Input: Read this: On 13 March, the upper Clyde port of Clydebank near Glasgow was bombed. All but seven of its 12,000 houses were damaged. Many more ports were attacked. Plymouth was attacked five times before the end of the month while Belfast, Hull, and Cardiff were hit. Cardiff was bombed on three nights, Portsmouth centre was devastated by five raids. The rate of civilian housing lost was averaging 40,000 people per week dehoused in September 1940. In March 1941, two raids on Plymouth and London dehoused 148,000 people. Still, while heavily damaged, British ports continued to support war industry and supplies from North America continued to pass through them while the Royal Navy continued to operate in Plymouth, Southampton, and Portsmouth. Plymouth in particular, because of its vulnerable position on the south coast and close proximity to German air bases, was subjected to the heaviest attacks. On 10/11 March, 240 bombers dropped 193 tons of high explosives and 46,000 incendiaries. Many houses and commercial centres were heavily damaged, the electrical supply was knocked out, and five oil tanks and two magazines exploded. Nine days later, two waves of 125 and 170 bombers dropped heavy bombs, including 160 tons of high explosive and 32,000 incendiaries. Much of the city centre was destroyed. Damage was inflicted on the port installations, but many bombs fell on the city itself. On 17 April 346 tons of explosives and 46,000 incendiaries were dropped from 250 bombers led by KG 26. The damage was considerable, and the Germans also used aerial mines. Over 2,000 AAA shells were fired, destroying two Ju 88s. By the end of the air campaign over Britain, only eight percent of the German effort against British ports was made using mines.
Question: What did the Germans use along with incendiaries and bombs?

Output: aerial mines


Input: Read this: In contrast, Europe has a greater history of unitary states than North America, thus European "federalism" argues for a weaker central government, relative to a unitary state. The modern American usage of the word is much closer to the European sense. As the power of the Federal government has increased, some people have perceived a much more unitary state than they believe the Founding Fathers intended. Most people politically advocating "federalism" in the United States argue in favor of limiting the powers of the federal government, especially the judiciary (see Federalist Society, New Federalism).
Question: Who has a lesser history of unitary states? 

Output:
unanswerable