Problem: Given the question: Extract the answer to the question from the following context. Question: What is the end goal of the towers using the climbing elevators? Context: A climbing elevator is a self-ascending elevator with its own propulsion. The propulsion can be done by an electric or a combustion engine. Climbing elevators are used in guyed masts or towers, in order to make easy access to parts of these constructions, such as flight safety lamps for maintenance. An example would be the Moonlight towers in Austin, Texas, where the elevator holds only one person and equipment for maintenance. The Glasgow Tower — an observation tower in Glasgow, Scotland — also makes use of two climbing elevators.
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The answer is:
maintenance


Problem: Given the question: Extract the answer to the question from the following context. Question: Legal time is time which is? Context: In Britain, Willett's 1907 proposal used the term daylight saving, but by 1911 the term summer time replaced daylight saving time in draft legislation. Continental Europe uses similar phrases, such as Sommerzeit in Germany, zomertijd in Dutch-speaking regions, kesäaika in Finland, horario de verano or hora de verano in Spain and heure d'été in France, whereas in Italy the term is ora legale, that is, legal time (legally enforced time) as opposed to "ora solare", solar time, in winter.
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The answer is:
legally enforced


Problem: Given the question: Extract the answer to the question from the following context. Question: This was started around the? Context: The original idea of a Chinese satellite navigation system was conceived by Chen Fangyun and his colleagues in the 1980s. According to the China National Space Administration, the development of the system would be carried out in three steps:
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The answer is:
1980s