The problem: Answer a question about this article:
There are many notable contributors to the field of Chinese science throughout the ages. One of the best examples would be Shen Kuo (1031–1095), a polymath scientist and statesman who was the first to describe the magnetic-needle compass used for navigation, discovered the concept of true north, improved the design of the astronomical gnomon, armillary sphere, sight tube, and clepsydra, and described the use of drydocks to repair boats. After observing the natural process of the inundation of silt and the find of marine fossils in the Taihang Mountains (hundreds of miles from the Pacific Ocean), Shen Kuo devised a theory of land formation, or geomorphology. He also adopted a theory of gradual climate change in regions over time, after observing petrified bamboo found underground at Yan'an, Shaanxi province. If not for Shen Kuo's writing, the architectural works of Yu Hao would be little known, along with the inventor of movable type printing, Bi Sheng (990-1051). Shen's contemporary Su Song (1020–1101) was also a brilliant polymath, an astronomer who created a celestial atlas of star maps, wrote a pharmaceutical treatise with related subjects of botany, zoology, mineralogy, and metallurgy, and had erected a large astronomical clocktower in Kaifeng city in 1088. To operate the crowning armillary sphere, his clocktower featured an escapement mechanism and the world's oldest known use of an endless power-transmitting chain drive.
Who discovered the idea of true north?
****
The answer: Shen Kuo


The problem: Answer a question about this article:
Paris' most popular sport clubs are the association football club Paris Saint-Germain F.C. and the rugby union club Stade Français. The 80,000-seat Stade de France, built for the 1998 FIFA World Cup, is located just north of Paris in the commune of Saint-Denis. It is used for football, rugby union and track and field athletics. It hosts the French national football team for friendlies and major tournaments qualifiers, annually hosts the French national rugby team's home matches of the Six Nations Championship, and hosts several important matches of the Stade Français rugby team. In addition to Paris Saint-Germain FC, the city has a number of other amateur football clubs: Paris FC, Red Star, RCF Paris and Stade Français Paris.
What is the rugby club in Paris?
****
The answer: Stade Français


The problem: Answer a question about this article:
The Houston–The Woodlands–Sugar Land metropolitan area is served by one public television station and two public radio stations. KUHT (HoustonPBS) is a PBS member station and is the first public television station in the United States. Houston Public Radio is listener-funded and comprises two NPR member stations: KUHF (KUHF News) and KUHA (Classical 91.7). KUHF is news/talk radio and KUHA is a classical music station. The University of Houston System owns and holds broadcasting licenses to KUHT, KUHF, and KUHA. The stations broadcast from the Melcher Center for Public Broadcasting, located on the campus of the University of Houston.
What stations comprise Houston Public Radio?
****
The answer: KUHF (KUHF News) and KUHA (Classical 91.7)


The problem: Answer a question about this article:
Geography effects solar energy potential because areas that are closer to the equator have a greater amount of solar radiation. However, the use of photovoltaics that can follow the position of the sun can significantly increase the solar energy potential in areas that are farther from the equator. Time variation effects the potential of solar energy because during the nighttime there is little solar radiation on the surface of the Earth for solar panels to absorb. This limits the amount of energy that solar panels can absorb in one day. Cloud cover can effect the potential of solar panels because clouds block incoming light from the sun and reduce the light available for solar cells.
Why does time have an effect of the amount of available solar energy?
****
The answer:
during the nighttime there is little solar radiation on the surface of the Earth for solar panels to absorb