Article: Oklahoma is in the nation's middle percentile in per capita spending on the arts, ranking 17th, and contains more than 300 museums. The Philbrook Museum of Tulsa is considered one of the top 50 fine art museums in the United States, and the Sam Noble Oklahoma Museum of Natural History in Norman, one of the largest university-based art and history museums in the country, documents the natural history of the region. The collections of Thomas Gilcrease are housed in the Gilcrease Museum of Tulsa, which also holds the world's largest, most comprehensive collection of art and artifacts of the American West.

Question: How many museums are in Oklahoma?
Ans: more than 300

Article: Population growth is higher than the national average, with a 6.4% increase, in the Somerset County Council area, since 1991, and a 17% increase since 1981. The population density is 1.4 persons per hectare, which can be compared to 2.07 persons per hectare for the South West region. Within the county, population density ranges 0.5 in West Somerset to 2.2 persons per hectare in Taunton Deane. The percentage of the population who are economically active is higher than the regional and national average, and the unemployment rate is lower than the regional and national average.

Question: What is the population growth rate of Somerset county
Ans: Population growth is higher than the national average, with a 6.4% increase, in the Somerset County Council area, since 1991, and a 17% increase since 1981

Article: Nanjing, with a total land area of 6,598 square kilometres (2,548 sq mi), is situated in the heartland of drainage area of lower reaches of Yangtze River, and in Yangtze River Delta, one of the largest economic zones of China. The Yangtze River flows past the west side and then north side of Nanjing City, while the Ningzheng Ridge surrounds the north, east and south side of the city. The city is 300 kilometres (190 mi) west-northwest of Shanghai, 1,200 kilometres (750 mi) south-southeast of Beijing, and 1,400 kilometres (870 mi) east-northeast of Chongqing. The downstream Yangtze River flows from Jiujiang, Jiangxi, through Anhui and Jiangsu to East Sea, north to drainage basin of downstream Yangtze is Huai River basin and south to it is Zhe River basin, and they are connected by the Grand Canal east to Nanjing. The area around Nanjing is called Hsiajiang (, Downstream River) region, with Jianghuai () stressing northern part and Jiangzhe () stressing southern part. The region is also known as Dongnan (, South East, the Southeast) and Jiangnan (, River South, south of Yangtze).

Question: How large is Nanjing, in miles?
Ans: 2,548 sq mi

Article: In the last two decades, photovoltaics (PV), also known as solar PV, has evolved from a pure niche market of small scale applications towards becoming a mainstream electricity source. A solar cell is a device that converts light directly into electricity using the photoelectric effect. The first solar cell was constructed by Charles Fritts in the 1880s. In 1931 a German engineer, Dr Bruno Lange, developed a photo cell using silver selenide in place of copper oxide. Although the prototype selenium cells converted less than 1% of incident light into electricity, both Ernst Werner von Siemens and James Clerk Maxwell recognized the importance of this discovery. Following the work of Russell Ohl in the 1940s, researchers Gerald Pearson, Calvin Fuller and Daryl Chapin created the crystalline silicon solar cell in 1954. These early solar cells cost 286 USD/watt and reached efficiencies of 4.56%. By 2012 available efficiencies exceed 20% and the maximum efficiency of research photovoltaics is over 40%.

Question: In the 1880s, who constructed the first solar cell?
Ans:
Charles Fritts