Problem: I know that the answer to the question "What party was Frederick II a part of?" is in "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.". Can you tell me what it is?

A: Salian dynasty


Problem: I know that the answer to the question "Which would be a worse time to invest in the stock market, 2007 or 2010?" is in "London's largest industry is finance, and its financial exports make it a large contributor to the UK's balance of payments. Around 325,000 people were employed in financial services in London until mid-2007. London has over 480 overseas banks, more than any other city in the world. Over 85 percent (3.2 million) of the employed population of greater London works in the services industries. Because of its prominent global role, London's economy had been affected by the Late-2000s financial crisis. However, by 2010 the City has recovered; put in place new regulatory powers, proceeded to regain lost ground and re-established London's economic dominance. The City of London is home to the Bank of England, London Stock Exchange, and Lloyd's of London insurance market.". Can you tell me what it is?

A: 2007


Problem: I know that the answer to the question "What type of music medium is enjoying a boost?" is in "In 2014 artist Jack White sold 40,000 copies of his second solo release, Lazaretto, on vinyl. The sales of the record beat the largest sales in one week on vinyl since 1991. The sales record was previously held by Pearl Jam's, Vitalogy, which sold 34,000 copies in one week in 1994. In 2014, the sale of vinyl records was the only physical music medium with increasing sales with relation to the previous year. Sales of other mediums including individual digital tracks, digital albums and compact discs have fallen, the latter having the greatest drop-in-sales rate.". Can you tell me what it is?

A: vinyl


Problem: I know that the answer to the question "what is OKCFD?" is in "Oklahoma City is protected by the Oklahoma City Fire Department (OKCFD), which employs 1015 paid, professional firefighters. The current Chief of Department is G. Keith Bryant, the department is also commanded by three Deputy Chiefs, who – along with the department chief – oversee the Operational Services, Prevention Services, and Support Services bureaus. The OKCFD currently operates out of 37 fire stations, located throughout the city in six battalions. The OKCFD also operates a fire apparatus fleet of 36 engines (including 30 paramedic engines), 13 ladders, 16 brush patrol units, six water tankers, two hazardous materials units, one Technical Rescue Unit, one Air Supply Unit, six Arson Investigation Units, and one Rehabilitation Unit. Each engine is staffed with a driver, an officer, and one to two firefighters, while each ladder company is staffed with a driver, an officer, and one firefighter. Minimum staffing per shift is 213 personnel. The Oklahoma City Fire Department responds to over 70,000 emergency calls annually.". Can you tell me what it is?

A:
professional firefighters