Problem: Nigeria:

Beginning in 1979, Nigerians participated in a brief return to democracy when Olusegun Obasanjo transferred power to the civilian regime of Shehu Shagari. The Shagari government became viewed as corrupt and incompetent by virtually all sectors of Nigerian society. The military coup of Muhammadu Buhari shortly after the regime's fraudulent re-election in 1984 was generally viewed as a positive development. Buhari promised major reforms, but his government fared little better than its predecessor. His regime was overthrown by another military coup in 1985.

How did Nigerians view the Shagari administration?
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A: corrupt and incompetent


Problem: Alloy:

The term alloy is used to describe a mixture of atoms in which the primary constituent is a metal. The primary metal is called the base, the matrix, or the solvent. The secondary constituents are often called solutes. If there is a mixture of only two types of atoms, not counting impurities, such as a copper-nickel alloy, then it is called a binary alloy. If there are three types of atoms forming the mixture, such as iron, nickel and chromium, then it is called a ternary alloy. An alloy with four constituents is a quaternary alloy, while a five-part alloy is termed a quinary alloy. Because the percentage of each constituent can be varied, with any mixture the entire range of possible variations is called a system. In this respect, all of the various forms of an alloy containing only two constituents, like iron and carbon, is called a binary system, while all of the alloy combinations possible with a ternary alloy, such as alloys of iron, carbon and chromium, is called a ternary system.

What is the name of an alloy that has  four constituents?
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A: quaternary alloy


Problem: Korean War:

The North Korean contributions to the Chinese Communist victory were not forgotten after the creation of the People's Republic of China in 1949. As a token of gratitude, between 50,000 and 70,000 Korean veterans that served in the PLA were sent back along with their weapons, and they later played a significant role in the initial invasion of South Korea. China promised to support the North Koreans in the event of a war against South Korea. The Chinese support created a deep division between the Korean Communists, and Kim Il-sung's authority within the Communist party was challenged by the Chinese faction led by Pak Il-yu, who was later purged by Kim.

What caused a problem within the Korean Communist Party?
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A: Chinese support


Problem: Frédéric Chopin:

In 1817 the Saxon Palace was requisitioned by Warsaw's Russian governor for military use, and the Warsaw Lyceum was reestablished in the Kazimierz Palace (today the rectorate of Warsaw University). Fryderyk and his family moved to a building, which still survives, adjacent to the Kazimierz Palace. During this period, Fryderyk was sometimes invited to the Belweder Palace as playmate to the son of the ruler of Russian Poland, Grand Duke Constantine; he played the piano for the Duke and composed a march for him. Julian Ursyn Niemcewicz, in his dramatic eclogue, "Nasze Przebiegi" ("Our Discourses", 1818), attested to "little Chopin's" popularity.

In one of his works who affirmed the popularity of Chopin as a child?
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A:
Julian Ursyn Niemcewicz