Input: Article: The Sanskrit grammatical tradition, Vyakarana, one of the six Vedangas, began in the late Vedic period and culminated in the Astadhyayi of Panini, which consists of 3990 sutras (ca. fifth century BCE). About a century after Panini (around 400 BCE), Katyayana composed Vartikas on the Panini sutras. Patanjali, who lived three centuries after Panini, wrote the Mahabhasya, the "Great Commentary" on the Astadhyayi and Vartikas. Because of these three ancient Vyakaranins (grammarians), this grammar is called Trimuni Vyakarana. To understand the meaning of the sutras, Jayaditya and Vamana wrote a commentary, the Kasika, in 600 CE. Paninian grammar is based on 14 Shiva sutras (aphorisms), where the whole matrika (alphabet) is abbreviated. This abbreviation is called the Pratyahara.

Now answer this question: What is the abbreviated alphabet called?

Output: Pratyahara

Article: Mexico City is served by the Sistema de Transporte Colectivo, a 225.9 km (140 mi) metro system, which is the largest in Latin America. The first portions were opened in 1969 and it has expanded to 12 lines with 195 stations. The metro is one of the busiest in the world transporting approximately 4.5 million people every day, surpassed only by subway lines in Moscow (7.5 million), Tokyo (5.9 million), and New York City (5.1 million). It is heavily subsidized, and has some of the lowest fares in the world, each trip costing 5.00 pesos from 05:00 am to midnight. Several stations display pre-Columbian artifacts and architecture that were discovered during the metro's construction.[citation needed] However, the metro covers less than half of the total urban area. The Metro stations are also differentiated by the use of icons and glyphs which were proposed for people who could not read. The specific icons were developed based on historical (characters, sites, pre-Hispanic motifs), linguistic, symbolic (glyphs) or location references and has being emulated in further transportations alternatives in the City and in other Mexican cities. Mexico City is the only city in the world to use the icon reference and has become a popular culture trademark for the city.

Question: How many lines are in the metro system?
Ans: 12

Here is a question about this article: Layer III audio can also use a "bit reservoir", a partially full frame's ability to hold part of the next frame's audio data, allowing temporary changes in effective bitrate, even in a constant bitrate stream. Internal handling of the bit reservoir increases encoding delay.[citation needed]
What is the answer to this question: A large benefit of a bit reservoir is that you can use it even while encoding what kind of stream?
****
So... constant bitrate

The problem: Answer a question about this article:
Eisenhower returned to the U.S. in December 1939 and was assigned as a battalion commander and regimental executive officer of the 15th Infantry at Fort Lewis, Washington. In March 1941 he was promoted to colonel and assigned as chief of staff of the newly activated IX Corps under Major General Kenyon Joyce. In June 1941, he was appointed Chief of Staff to General Walter Krueger, Commander of the 3rd Army, at Fort Sam Houston in San Antonio, Texas. After successfully participating in the Louisiana Maneuvers, he was promoted to brigadier general on October 3, 1941. Although his administrative abilities had been noticed, on the eve of the U.S. entry into World War II he had never held an active command above a battalion and was far from being considered by many as a potential commander of major operations.
At what military installation was the 15th Infantry based?
****
The answer: Fort Lewis

Problem: Please answer a question about the following article about Alexander Graham Bell:
Unsure of his future, he first contemplated returning to London to complete his studies, but decided to return to Boston as a teacher. His father helped him set up his private practice by contacting Gardiner Greene Hubbard, the president of the Clarke School for the Deaf for a recommendation. Teaching his father's system, in October 1872, Alexander Bell opened his "School of Vocal Physiology and Mechanics of Speech" in Boston, which attracted a large number of deaf pupils, with his first class numbering 30 students. While he was working as a private tutor, one of his most famous pupils was Helen Keller, who came to him as a young child unable to see, hear, or speak. She was later to say that Bell dedicated his life to the penetration of that "inhuman silence which separates and estranges." In 1893, Keller performed the sod-breaking ceremony for the construction of the new Bell's new Volta Bureau, dedicated to "the increase and diffusion of knowledge relating to the deaf".
In what year did Bell open his own school?
A: 1872

Question: Read this and answer the question

A mummified man, determined to be 5,000 years old, was discovered on a glacier at the AustrianItalian border in 1991. By the 6th century BC, the Celtic La Tene culture was well established. Hannibal famously crossed the Alps with a herd of elephants, and the Romans had settlements in the region. In 1800 Napoleon crossed one of the mountain passes with an army of 40,000. The 18th and 19th centuries saw an influx of naturalists, writers, and artists, in particular the Romantics, followed by the golden age of alpinism as mountaineers began to ascend the peaks. In World War II, Adolf Hitler kept a base of operation in the Bavarian Alps throughout the war.

Where was Adolf Hitlers base of operation during World War 2?
Answer:
Bavarian Alps