Problem: Airports may also contain premium and VIP services. The premium and VIP services may include express check-in and dedicated check-in counters. These services are usually reserved for First and Business class passengers, premium frequent flyers, and members of the airline's clubs. Premium services may sometimes be open to passengers who are members of a different airline's frequent flyer program. This can sometimes be part of a reciprocal deal, as when multiple airlines are part of the same alliance, or as a ploy to attract premium customers away from rival airlines.
What do rival airlines offer to customers?
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Answer: unanswerable

Problem: where the uncertainty is given as the standard deviation of the measured value from its expected value. There are a number of other such pairs of physically measurable values which obey a similar rule. One example is time vs. energy. The either-or nature of uncertainty forces measurement attempts to choose between trade offs, and given that they are quanta, the trade offs often take the form of either-or (as in Fourier analysis), rather than the compromises and gray areas of time series analysis.
What type of analysis fits the either-or nature of the uncertainty?
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Answer: Fourier analysis

Problem: In France, simultaneously, the towering figure of the Gothic Revival was Eugene Viollet-le-Duc, who outdid historical Gothic constructions to create a Gothic as it ought to have been, notably at the fortified city of Carcassonne in the south of France and in some richly fortified keeps for industrial magnates. Viollet-le-Duc compiled and coordinated an Encyclopedie medievale that was a rich repertory his contemporaries mined for architectural details. He effected vigorous restoration of crumbling detail of French cathedrals, including the Abbey of Saint-Denis and famously at Notre Dame de Paris, where many of whose most "Gothic" gargoyles are Viollet-le-Duc's. He taught a generation of reform-Gothic designers and showed how to apply Gothic style to modern structural materials, especially cast iron.
What modern building material did Viollet-le-Duc teach reform Gothic designers to avoid?
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Answer:
unanswerable