Problem: In nature, the red color of blood comes from hemoglobin, the iron-containing protein found in the red blood cells of all vertebrates. The red color of the Grand Canyon and other geological features is caused by hematite or red ochre, both forms of iron oxide. It also causes the red color of the planet Mars. The red sky at sunset and sunrise is caused by an optical effect known as Rayleigh scattering, which, when the sun is low or below the horizon, increases the red-wavelength light that reaches the eye. The color of autumn leaves is caused by pigments called anthocyanins, which are produced towards the end of summer, when the green chlorophyll is no longer produced. One to two percent of the human population has red hair; the color is produced by high levels of the reddish pigment pheomelanin (which also accounts for the red color of the lips) and relatively low levels of the dark pigment eumelanin.
Why does a sky turn red when the evening comes?
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Answer: Rayleigh scattering

Problem: Industrialization is the process of social and economic change whereby a human group is transformed from a pre-industrial society into an industrial one. It is a subdivision of a more general modernization process, where social change and economic development are closely related with technological innovation, particularly with the development of large-scale energy and metallurgy production. It is the extensive organization of an economy for the purpose of manufacturing. Industrialization also introduces a form of philosophical change, where people obtain a different attitude towards their perception of nature.
industrialization is a subdivision of what general process?
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Answer: technological innovation

Problem: Around the sixth century AD, a tribe of Slavs arrived in a portion of Central Europe. According to legend they were led by a hero named Cech, from whom the word "Czech" derives. The ninth century brought the state of Great Moravia, whose first ruler (Rastislav of Moravia) invited Byzantine ruler Michael III to send missionaries in an attempt to reduce the influence of East Francia on religious and political life in his country. These missionaries, Constantine and Methodius, helped to convert the Czechs from traditional Slavic paganism to Christianity and established a church system. They also brought the Glagolitic alphabet to the West Slavs, whose language was previously unwritten. This language, later known as Proto-Czech, was beginning to separate from its fellow West Slavic hatchlings Proto-Slovak, Proto-Polish and Proto-Sorbian. Among other features, Proto-Czech was marked by its ephemeral use of the voiced velar fricative consonant (//) and consistent stress on the first syllable.
When did Rastislav of Moravia arrive in Glagolitic?
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Answer:
unanswerable