Article: Later, von Neumann suggested a new method of linear programming, using the homogeneous linear system of Gordan (1873), which was later popularized by Karmarkar's algorithm. Von Neumann's method used a pivoting algorithm between simplices, with the pivoting decision determined by a nonnegative least squares subproblem with a convexity constraint (projecting the zero-vector onto the convex hull of the active simplex). Von Neumann's algorithm was the first interior point method of linear programming.

Question: What did von Neuman's method use?
Ans: pivoting algorithm between simplices

Article: Mexico city primarily rests on what was Lake Texcoco. Seismic activity is frequent here. Lake Texcoco was drained starting from the 17th century. Although none of the lake waters remain, the city rests on the lake bed's heavily saturated clay. This soft base is collapsing due to the over-extraction of groundwater, called groundwater-related subsidence. Since the beginning of the 20th century the city has sunk as much as nine metres (30 feet) in some areas. This sinking is causing problems with runoff and wastewater management, leading to flooding problems, especially during the rainy season. The entire lake bed is now paved over and most of the city's remaining forested areas lie in the southern boroughs of Milpa Alta, Tlalpan and Xochimilco.

Question: Where are most of the trees located in Mexico City?
Ans: southern boroughs

Article: In 1981, the new US President Ronald Reagan pursued a hard line approach to Libya, erroneously considering it a puppet regime of the Soviet Union. In turn, Gaddafi played up his commercial relationship with the Soviets, visiting Moscow again in April 1981 and 1985, and threatening to join the Warsaw Pact. The Soviets were nevertheless cautious of Gaddafi, seeing him as an unpredictable extremist. Beginning military exercises in the Gulf of Sirte an area of sea that Libya claimed as a part of its territorial waters in August 1981 the U.S. shot down two Libyan Su-22 planes monitoring them. Closing down Libya's embassy in Washington, D.C., Reagan advised U.S. companies operating in the country to reduce the number of American personnel stationed there. In March 1982, the U.S. implemented an embargo of Libyan oil, and in January 1986 ordered all U.S. companies to cease operating in the country, although several hundred workers remained. Diplomatic relations also broke down with the U.K., after Libyan diplomats were accused in the shooting death of Yvonne Fletcher, a British policewoman stationed outside their London embassy, in April 1984. In Spring 1986, the U.S. Navy again began performing exercises in the Gulf of Sirte; the Libyan military retaliated, but failed as the U.S. sank several Libyan ships.

Question: What was the occupation of Yvonne Fletcher?
Ans: policewoman

Article: Grazing organisms may also kill their prey species, but this is seldom the case. While some herbivores like zooplankton live on unicellular phytoplankton and therefore, by the individualized nature of the organism, kill their prey, many only eat a small part of the plant. Grazing livestock may pull some grass out at the roots, but most is simply grazed upon, allowing the plant to regrow once again. Kelp is frequently grazed in subtidal kelp forests, but regrows at the base of the blade continuously to cope with browsing pressure. Animals may also be 'grazed' upon; female mosquitos land on hosts briefly to gain sufficient proteins for the development of their offspring. Starfish may be grazed on, being capable of regenerating lost arms.

Question: Do grazing organisms often kill their prey?
Ans:
seldom