In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
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Question: Why did the Ottonian dynasty get replaced by the Salian dynasty?, Context: During the early High Middle Ages, Germany was ruled by the Ottonian dynasty, which struggled to control the powerful dukes ruling over territorial duchies tracing back to the Migration period. In 1024, they were replaced by the Salian dynasty, who famously clashed with the papacy under Emperor Henry IV (r. 1084–1105) over church appointments as part of the Investiture Controversy. His successors continued to struggle against the papacy as well as the German nobility. A period of instability followed the death of Emperor Henry V (r. 1111–25), who died without heirs, until Frederick I Barbarossa (r. 1155–90) took the imperial throne. Although he ruled effectively, the basic problems remained, and his successors continued to struggle into the 13th century. Barbarossa's grandson Frederick II (r. 1220–1250), who was also heir to the throne of Sicily through his mother, clashed repeatedly with the papacy. His court was famous for its scholars and he was often accused of heresy. He and his successors faced many difficulties, including the invasion of the Mongols into Europe in the mid-13th century. Mongols first shattered the Kievan Rus' principalities and then invaded Eastern Europe in 1241, 1259, and 1287.

Answer: struggled to control the powerful dukes ruling over territorial duchies


Question: What distinguishes the district of Houston?, Context: Houston was incorporated in 1837 under the ward system of representation. The ward designation is the progenitor of the eleven current-day geographically oriented Houston City Council districts. Locations in Houston are generally classified as either being inside or outside the Interstate 610 Loop. The inside encompasses the central business district and many residential neighborhoods that predate World War II. More recently, high-density residential areas have been developed within the loop. The city's outlying areas, suburbs and enclaves are located outside of the loop. Beltway 8 encircles the city another 5 miles (8.0 km) farther out.

Answer: classified as either being inside or outside the Interstate 610 Loop


Question: What happened in the lower part of the country?, Context: Representatives of the Polish government officially took over the civilian administration of the southern part of East Prussia on 23 May 1945. Subsequently Polish expatriates from Polish lands annexed by the Soviet Union as well as Ukrainians and Lemkos from southern Poland, expelled in Operation Vistula in 1947, were settled in the southern part of East Prussia, now the Polish Warmian-Masurian Voivodeship. In 1950 the Olsztyn Voivodeship counted 689,000 inhabitants, 22.6% of them coming from areas annexed by the Soviet Union, 10% Ukrainians, and 18.5% of them pre-war inhabitants. The remaining pre-war population was treated as Germanized Poles and a policy of re-Polonization was pursued throughout the country Most of these "Autochthones" chose to emigrate to West Germany from the 1950s through 1970s (between 1970 and 1988 55,227 persons from Warmia and Masuria moved to Western Germany). Local toponyms were Polonised by the Polish Commission for the Determination of Place Names.

Answer:
Subsequently Polish expatriates from Polish lands annexed by the Soviet Union as well as Ukrainians and Lemkos from southern Poland, expelled in Operation Vistula in 1947, were settled in the southern part of East Prussia