Q: Extract the answer to the question from the following context. Question: Which ParkScore factor involves the people who could walk to the park on a daily basis? Context: In its 2013 ParkScore ranking, The Trust for Public Land reported that the park system in New York City was the second best park system among the 50 most populous U.S. cities, behind the park system of Minneapolis. ParkScore ranks urban park systems by a formula that analyzes median park size, park acres as percent of city area, the percent of city residents within a half-mile of a park, spending of park services per resident, and the number of playgrounds per 10,000 residents.
A: percent of city residents within a half-mile of a park

Q: Extract the answer to the question from the following context. Question: What happened on 1 August 1919? Context: In February 1918, he was appointed Officer in Charge of Boys at the Royal Naval Air Service's training establishment at Cranwell. With the establishment of the Royal Air Force two months later and the transfer of Cranwell from Navy to Air Force control, he transferred from the Royal Navy to the Royal Air Force. He was appointed Officer Commanding Number 4 Squadron of the Boys' Wing at Cranwell until August 1918, before reporting to the RAF's Cadet School at St Leonards-on-Sea where he completed a fortnight's training and took command of a squadron on the Cadet Wing. He was the first member of the royal family to be certified as a fully qualified pilot. During the closing weeks of the war, he served on the staff of the RAF's Independent Air Force at its headquarters in Nancy, France. Following the disbanding of the Independent Air Force in November 1918, he remained on the Continent for two months as a staff officer with the Royal Air Force until posted back to Britain. He accompanied the Belgian monarch King Albert on his triumphal reentry into Brussels on 22 November. Prince Albert qualified as an RAF pilot on 31 July 1919 and gained a promotion to squadron leader on the following day.
A: promotion to squadron leader

Q: Extract the answer to the question from the following context. Question: What country helped drive the thirst? Context: All over Europe rulers and city governments began to create universities to satisfy a European thirst for knowledge, and the belief that society would benefit from the scholarly expertise generated from these institutions. Princes and leaders of city governments perceived the potential benefits of having a scholarly expertise develop with the ability to address difficult problems and achieve desired ends. The emergence of humanism was essential to this understanding of the possible utility of universities as well as the revival of interest in knowledge gained from ancient Greek texts.
A: ancient Greek

Q: Extract the answer to the question from the following context. Question: What was the density of particulate matter in the air a day after smog had entered Central and Eastern parts of China? Context: A dense wave of smog began in the Central and Eastern part of China on 2 December 2013 across a distance of around 1,200 kilometres (750 mi), including Tianjin, Hebei, Shandong, Jiangsu, Anhui, Shanghai and Zhejiang. A lack of cold air flow, combined with slow-moving air masses carrying industrial emissions, collected airborne pollutants to form a thick layer of smog over the region. The heavy smog heavily polluted central and southern Jiangsu Province, especially in and around Nanjing, with its AQI pollution Index at "severely polluted" for five straight days and "heavily polluted" for nine. On 3 December 2013, levels of PM2.5 particulate matter average over 943 micrograms per cubic metre, falling to over 338 micrograms per cubic metre on 4 December 2013. Between 3:00 pm, 3 December and 2:00pm, 4 December local time, several expressways from Nanjing to other Jiangsu cities were closed, stranding dozens of passenger buses in Zhongyangmen bus station. From 5 to 6 December, Nanjing issued a red alert for air pollution and closed down all kindergarten through middle schools. Children's Hospital outpatient services increased by 33 percent; general incidence of bronchitis, pneumonia, upper respiratory tract infections significantly increased. The smog dissipated 12 December. Officials blamed the dense pollution on lack of wind, automobile exhaust emissions under low air pressure, and coal-powered district heating system in North China region. Prevailing winds blew low-hanging air masses of factory emissions (mostly SO2) towards China's east coast.
A:
943 micrograms per cubic metre