The problem: Answer a question about this article:
Guinea-Bissau was once part of the kingdom of Gabu, part of the Mali Empire; parts of this kingdom persisted until the 18th century. Other parts of the territory in the current country were considered by the Portuguese as part of their empire. Portuguese Guinea was known as the Slave Coast, as it was a major area for the exportation of African slaves by Europeans to the western hemisphere. Previously slaves had been traded by Arabs north to the northern part of Africa and into the Middle East.
Who traded slaves into the Middle East?
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The answer: Arabs

The problem: Answer a question about this article:
Up to 1990, English, German and Afrikaans were official languages. Long before Namibia's independence from South Africa, SWAPO was of the opinion that the country should become officially monolingual, choosing this approach in contrast to that of its neighbour South Africa (which granted all 11 of its major languages official status), which was seen by them as "a deliberate policy of ethnolinguistic fragmentation." Consequently, SWAPO instituted English as the sole official language of Namibia though only about 3% of the population speaks it as a home language. Its implementation is focused on the civil service, education and the broadcasting system. Some other languages have received semi-official recognition by being allowed as medium of instruction in primary schools. It is expected of private schools to follow the same policy as state schools, and "English language" is a compulsory subject. As in other postcolonial African societies, the push for monolingual instruction and policy has resulted in a high rate of school drop-outs and of individuals whose academic competence in any language is low.
German, English, and Afrikaans were the official languages until when in Namibia?
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The answer: 1990

The problem: Answer a question about this article:
Arabic translation efforts and techniques are important to Western translation traditions due to centuries of close contacts and exchanges. Especially after the Renaissance, Europeans began more intensive study of Arabic and Persian translations of classical works as well as scientific and philosophical works of Arab and oriental origins. Arabic and, to a lesser degree, Persian became important sources of material and perhaps of techniques for revitalized Western traditions, which in time would overtake the Islamic and oriental traditions.
What helped revitalize Western translation traditions from Arabic?
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The answer: techniques

The problem: Answer a question about this article:
Hydrogen is highly soluble in many rare earth and transition metals and is soluble in both nanocrystalline and amorphous metals. Hydrogen solubility in metals is influenced by local distortions or impurities in the crystal lattice. These properties may be useful when hydrogen is purified by passage through hot palladium disks, but the gas's high solubility is a metallurgical problem, contributing to the embrittlement of many metals, complicating the design of pipelines and storage tanks.
Where can you find soluble hydrogen?
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The answer:
nanocrystalline and amorphous metals