input question: Extract the answer to the question from the following context. Question: Where was the centre of range measured from? Context: Initially, the station's range was officially a 40 kilometres radius of the Alexandra Palace transmitterin practice, however, transmissions could be picked up a good deal further away, and on one occasion in 1938 were picked up by engineers at RCA in New York, who were experimenting with a British television set.???
output answer: Alexandra Palace

input question: Extract the answer to the question from the following context. Question: What reduces a filaments life? Context: On 13 December 1904, Hungarian Sandor Just and Croatian Franjo Hanaman were granted a Hungarian patent (No. 34541) for a tungsten filament lamp that lasted longer and gave brighter light than the carbon filament. Tungsten filament lamps were first marketed by the Hungarian company Tungsram in 1904. This type is often called Tungsram-bulbs in many European countries. Filling a bulb with an inert gas such as argon or nitrogen retards the evaporation of the tungsten filament compared to operating it in a vacuum. This allows for greater temperatures and therefore greater efficacy with less reduction in filament life.???
output answer: a vacuum

input question: Extract the answer to the question from the following context. Question: What population increased by 77% in 20 years? Context: In recent years, the city has experienced steady population growth, and has been faced with the issue of accommodating more residents. In 2006, after growing by 4,000 citizens per year for the previous 16 years, regional planners expected the population of Seattle to grow by 200,000 people by 2040. However, former mayor Greg Nickels supported plans that would increase the population by 60%, or 350,000 people, by 2040 and worked on ways to accommodate this growth while keeping Seattle's single-family housing zoning laws. The Seattle City Council later voted to relax height limits on buildings in the greater part of Downtown, partly with the aim to increase residential density in the city centre. As a sign of increasing inner-city growth, the downtown population crested to over 60,000 in 2009, up 77% since 1990.???
output answer: downtown

input question: Extract the answer to the question from the following context. Question: Why does Miami not have a subway system Context: Beneath the plain lies the Biscayne Aquifer, a natural underground source of fresh water that extends from southern Palm Beach County to Florida Bay, with its highest point peaking around the cities of Miami Springs and Hialeah. Most of the Miami metropolitan area obtains its drinking water from this aquifer. As a result of the aquifer, it is not possible to dig more than 15 to 20 ft (5 to 6 m) beneath the city without hitting water, which impedes underground construction, though some underground parking garages exist. For this reason, the mass transit systems in and around Miami are elevated or at-grade.[citation needed]???
output answer:
the Biscayne Aquifer