Problem: Materialism:

Despite the large number of philosophical schools and subtle nuances between many, all philosophies are said to fall into one of two primary categories, which are defined in contrast to each other: Idealism, and materialism.[a] The basic proposition of these two categories pertains to the nature of reality, and the primary distinction between them is the way they answer two fundamental questions: "what does reality consist of?" and "how does it originate?" To idealists, spirit or mind or the objects of mind (ideas) are primary, and matter secondary. To materialists, matter is primary, and mind or spirit or ideas are secondary, the product of matter acting upon matter.

A materialist considers what as the least important?
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A: unanswerable

Problem: Neptune:

Meanwhile, Le Verrier by letter urged Berlin Observatory astronomer Johann Gottfried Galle to search with the observatory's refractor. Heinrich d'Arrest, a student at the observatory, suggested to Galle that they could compare a recently drawn chart of the sky in the region of Le Verrier's predicted location with the current sky to seek the displacement characteristic of a planet, as opposed to a fixed star. On the evening of 23 September 1846, the day Galle received the letter, he discovered Neptune within 1 of where Le Verrier had predicted it to be, about 12 from Adams' prediction. Challis later realised that he had observed the planet twice, on 4 and 12 August, but did not recognise it as a planet because he lacked an up-to-date star map and was distracted by his concurrent work on comet observations.

What did Galle suggest to Heinrich d'Arrest?
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A: unanswerable

Problem: Near East:

The geographical terms "Near East" and "Far East" referring to areas of the globe in or contiguous to the former British Empire and the neighboring colonies of the Dutch, Portuguese, Spanish and Germans, fit together as a pair based on the opposites of far and near, suggesting that they were innovated together. They appear together in the journals of the mid-19th century. Both terms were used before then with local British and American meanings: the near or far east of a field, village or shire.

When do the terms "Near East" and "Far East" appear together in journals?
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A: the mid-19th century

Problem: Light-emitting diode:

The most common symptom of LED (and diode laser) failure is the gradual lowering of light output and loss of efficiency. Sudden failures, although rare, can also occur. Early red LEDs were notable for their short service life. With the development of high-power LEDs the devices are subjected to higher junction temperatures and higher current densities than traditional devices. This causes stress on the material and may cause early light-output degradation. To quantitatively classify useful lifetime in a standardized manner it has been suggested to use L70 or L50, which are the runtimes (typically given in thousands of hours) at which a given LED reaches 70% and 50% of initial light output, respectively.

What is rare in LED lighting?
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A:
Sudden failures