Problem: PlayStation 3:

The PlayStation Store is an online virtual market available to users of Sony's PlayStation 3 (PS3) and PlayStation Portable (PSP) game consoles via the PlayStation Network. The Store offers a range of downloadable content both for purchase and available free of charge. Available content includes full games, add-on content, playable demos, themes and game and movie trailers. The service is accessible through an icon on the XMB on PS3 and PSP. The PS3 store can also be accessed on PSP via a Remote Play connection to PS3. The PSP store is also available via the PC application, Media Go. As of September 24, 2009, there have been over 600 million downloads from the PlayStation Store worldwide.

What do you click on in the PS3 interface to get to the PlayStation Store?
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A: an icon


Problem: In classical physics, an inertial reference frame is one in which an object that experiences no forces does not accelerate. In general relativity, an inertial frame of reference is one that is following a geodesic of space-time. An object that moves against a geodesic experiences a force. An object in free fall does not experience a force, because it is following a geodesic. An object standing on the earth, however, will experience a force, as it is being held against the geodesic by the surface of the planet. In light of this, the bucket of water rotating in empty space will experience a force because it rotates with respect to the geodesic. The water will become concave, not because it is rotating with respect to the distant stars, but because it is rotating with respect to the geodesic.
What is an object in free fall moving against?
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Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The Earth receives 174,000 terawatts (TW) of incoming solar radiation (insolation) at the upper atmosphere. Approximately 30% is reflected back to space while the rest is absorbed by clouds, oceans and land masses. The spectrum of solar light at the Earth's surface is mostly spread across the visible and near-infrared ranges with a small part in the near-ultraviolet. Most people around the world live in areas with insolation levels of 150 to 300 watts per square meter or 3.5 to 7.0 kWh/m2 per day.
The areas that people live in typically receive what range of kWh/m2 per day?
A: 3.5 to 7.0


Context and question: The most-viewed network in France, TF1, is in nearby Boulogne-Billancourt; France 2, France 3, Canal+, France 5, M6 (Neuilly-sur-Seine), Arte, D8, W9, NT1, NRJ 12, La Chaîne parlementaire, France 4, BFM TV, and Gulli are other stations located in and around the capital. Radio France, France's public radio broadcaster, and its various channels, is headquartered in Paris' 16th arrondissement. Radio France Internationale, another public broadcaster is also based in the city. Paris also holds the headquarters of the La Poste, France's national postal carrier.
What is the name of France's national postal carrier?
Answer: La Poste


Question: Human interference has nearly exterminated the trees in many areas, and, except for the beech forests of the Austrian Alps, forests of deciduous trees are rarely found after the extreme deforestation between the 17th and 19th centuries. The vegetation has changed since the second half of the 20th century, as the high alpine meadows cease to be harvested for hay or used for grazing which eventually might result in a regrowth of forest. In some areas the modern practice of building ski runs by mechanical means has destroyed the underlying tundra from which the plant life cannot recover during the non-skiing months, whereas areas that still practice a natural piste type of ski slope building preserve the fragile underlayers.
Is there an answer to this question: The practice of building ski runs by mechanical means has destroyed what?

Answer: the underlying tundra


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Brain tissue consumes a large amount of energy in proportion to its volume, so large brains place severe metabolic demands on animals. The need to limit body weight in order, for example, to fly, has apparently led to selection for a reduction of brain size in some species, such as bats. Most of the brain's energy consumption goes into sustaining the electric charge (membrane potential) of neurons. Most vertebrate species devote between 2% and 8% of basal metabolism to the brain. In primates, however, the percentage is much higher—in humans it rises to 20–25%. The energy consumption of the brain does not vary greatly over time, but active regions of the cerebral cortex consume somewhat more energy than inactive regions; this forms the basis for the functional brain imaging methods PET, fMRI, and NIRS. The brain typically gets most of its energy from oxygen-dependent metabolism of glucose (i.e., blood sugar), but ketones provide a major alternative source, together with contributions from medium chain fatty acids (caprylic and heptanoic acids), lactate, acetate, and possibly amino acids.
Other sources than glucose that provide energy to the brain are what?
A:
ketones