Problem: Compact disc:

A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode, the data can be read from the disc. In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.

Why is the data arranged in a spiral pattern?
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A: unanswerable


Problem: Namibia is one of few countries in the world to specifically address conservation and protection of natural resources in its constitution. Article 95 states, "The State shall actively promote and maintain the welfare of the people by adopting international policies aimed at the following: maintenance of ecosystems, essential ecological processes, and biological diversity of Namibia, and utilisation of living natural resources on a sustainable basis for the benefit of all Namibians, both present and future."
What is the smallest country in the world to address conservation in its constitution?
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Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Most animals indirectly use the energy of sunlight by eating plants or plant-eating animals. Most plants use light to convert inorganic molecules in their environment into carbohydrates, fats, proteins and other biomolecules, characteristically containing reduced carbon in the form of carbon-hydrogen bonds. Starting with carbon dioxide (CO2) and water (H2O), photosynthesis converts the energy of sunlight into chemical energy in the form of simple sugars (e.g., glucose), with the release of molecular oxygen. These sugars are then used as the building blocks for plant growth, including the production of other biomolecules. When an animal eats plants (or eats other animals which have eaten plants), the reduced carbon compounds in the food become a source of energy and building materials for the animal. They are either used directly to help the animal grow, or broken down, releasing stored solar energy, and giving the animal the energy required for motion.
What happens with the reduced carbon compounds in the food are broken down releasing stored solar energy?
A: giving the animal the energy required for motion


Context and question: Western Catalan comprises the two dialects of Northwestern Catalan and Valencian; the Eastern block comprises four dialects: Central Catalan, Balearic, Rossellonese, and Alguerese. Each dialect can be further subdivided in several subdialects.
What other divisions can be made of dialects?
Answer: subdialects


Question: On October 25, 1836, construction began on the Wilmington and Raleigh Railroad to connect the port city of Wilmington with the state capital of Raleigh. In 1849 the North Carolina Railroad was created by act of the legislature to extend that railroad west to Greensboro, High Point, and Charlotte. During the Civil War, the Wilmington-to-Raleigh stretch of the railroad would be vital to the Confederate war effort; supplies shipped into Wilmington would be moved by rail through Raleigh to the Confederate capital of Richmond, Virginia.
Is there an answer to this question: What direction did the North carolina railroad extend?

Answer: west


Problem: Arena Football League:

From 2000 to 2009, the AFL had its own developmental league, the af2. The AFL played 22 seasons from 1987 to 2008; internal issues caused the league to cancel its 2009 season, though the af2 did play. Later that year both the AFL and af2 were dissolved and reorganized as a new corporation comprising teams from both leagues, and the AFL returned in 2010. The Arena Football League has its headquarters in Chicago, Illinois.

When was the first AFL season played?
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A:
1987