input: Please answer the following: Extract the answer to the question from the following context. Question: Why is the lack of predation a problem for water features? Context: The elimination of wolves from Yellowstone National Park had profound impacts on the trophic pyramid. Without predation, herbivores began to over-graze many woody browse species, affecting the area's plant populations. In addition, wolves often kept animals from grazing in riparian areas, which protected beavers from having their food sources encroached upon. The removal of wolves had a direct effect on beaver populations, as their habitat became territory for grazing. Furthermore, predation keeps hydrological features such as creeks and streams in normal working order. Increased browsing on willows and conifers along Blacktail Creek due to a lack of predation caused channel incision because they helped slow the water down and hold the soil in place.
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output: predation keeps hydrological features such as creeks and streams in normal working order

Please answer this: Extract the answer to the question from the following context. Question: What is notable about Philadelphia? Context: The area's many universities and colleges make Philadelphia a top international study destination, as the city has evolved into an educational and economic hub. With a gross domestic product of $388 billion, Philadelphia ranks ninth among world cities and fourth in the nation. Philadelphia is the center of economic activity in Pennsylvania and is home to seven Fortune 1000 companies. The Philadelphia skyline is growing, with several nationally prominent skyscrapers. The city is known for its arts, culture, and history, attracting over 39 million domestic tourists in 2013. Philadelphia has more outdoor sculptures and murals than any other American city, and Fairmount Park is the largest landscaped urban park in the world. The 67 National Historic Landmarks in the city helped account for the $10 billion generated by tourism. Philadelphia is the birthplace of the United States Marine Corps, and is also the home of many U.S. firsts, including the first library (1731), first hospital (1751) and medical school (1765), first Capitol (1777), first stock exchange (1790), first zoo (1874), and first business school (1881). Philadelphia is the only World Heritage City in the United States.
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Answer: the city has evolved into an educational and economic hub

Problem: Extract the answer to the question from the following context. Question: Styli made of sapphire and osmium alloy replaced those made from what? Context: In 1931, RCA Victor introduced their vinyl-based Victrolac compound as a material for some unusual-format and special-purpose records. By the end of the 1930s vinyl's advantages of light weight, relative unbreakability and low surface noise had made it the material of choice for prerecorded radio programming and other critical applications. When it came to ordinary 78 rpm records, however, the much higher cost of the raw material, as well as its vulnerability to the heavy pickups and crudely mass-produced steel needles still commonly used in home record players, made its general substitution for shellac impractical at that time. During the Second World War, the United States Armed Forces produced thousands of 12-inch vinyl 78 rpm V-Discs for use by the troops overseas. After the war, the wider use of vinyl became more practical as new record players with relatively lightweight crystal pickups and precision-ground styli made of sapphire or an exotic osmium alloy proliferated. In late 1945, RCA Victor began offering special transparent red vinyl De Luxe pressings of some classical 78s, at a de luxe price. Later, Decca Records introduced vinyl Deccalite 78s, while other record companies came up with vinyl concoctions such as Metrolite, Merco Plastic and Sav-o-flex, but these were mainly used to produce "unbreakable" children's records and special thin vinyl DJ pressings for shipment to radio stations.

A: steel

Problem: Given the question: Extract the answer to the question from the following context. Question: Which caption speaks during a coin toss? Context: At the beginning of a match, an official tosses a coin and allows the captain of the visiting team call heads or tails. The captain of the team winning the coin toss is given the option of having first choice, or of deferring first choice to the other captain. The captain making first choice may either choose a) to kick off or receive the kick and the beginning of the half, or b) which direction of the field to play in. The remaining choice is given to the opposing captain. Before the resumption of play in the second half, the captain that did not have first choice in the first half is given first choice. Teams usually choose to defer, so it is typical for the team that wins the coin toss to kick to begin the first half and receive to begin the second.
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The answer is:
captain of the visiting team

input question: Extract the answer to the question from the following context. Question: Who was mentioned second; Compuware, the Renaissance Center or Quicken Loans? Context: A number of the city's downtown employers are relatively new, as there has been a marked trend of companies moving from satellite suburbs around Metropolitan Detroit into the downtown core.[citation needed] Compuware completed its world headquarters in downtown in 2003. OnStar, Blue Cross Blue Shield, and HP Enterprise Services are located at the Renaissance Center. PricewaterhouseCoopers Plaza offices are adjacent to Ford Field, and Ernst & Young completed its office building at One Kennedy Square in 2006. Perhaps most prominently, in 2010, Quicken Loans, one of the largest mortgage lenders, relocated its world headquarters and 4,000 employees to downtown Detroit, consolidating its suburban offices. In July 2012, the U.S. Patent and Trademark Office opened its Elijah J. McCoy Satellite Office in the Rivertown/Warehouse District as its first location outside Washington, D.C.'s metropolitan area.???
output answer: Renaissance Center

input question: Extract the answer to the question from the following context. Question: What was the title given to Athanasius which means first of his name? Context: Saint Athanasius of Alexandria (/nes/; Greek: , Athanasios Alexandrias; c. 296298 2 May 373), also called Athanasius the Great, Athanasius the Confessor or, primarily in the Coptic Orthodox Church, Athanasius the Apostolic, was the twentieth bishop of Alexandria (as Athanasius I). His episcopate lasted 45 years (c. 8 June 328 2 May 373), of which over 17 were spent in five exiles ordered by four different Roman emperors. Athanasius is a renowned Christian theologian, a Church Father, the chief defender of Trinitarianism against Arianism, and a noted Egyptian leader of the fourth century.???
output answer:
Athanasius I