This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

Providing 25% of Namibia's revenue, mining is the single most important contributor to the economy. Namibia is the fourth largest exporter of non-fuel minerals in Africa and the world's fourth largest producer of uranium. There has been significant investment in uranium mining and Namibia is set to become the largest exporter of uranium by 2015. Rich alluvial diamond deposits make Namibia a primary source for gem-quality diamonds. While Namibia is known predominantly for its gem diamond and uranium deposits, a number of other minerals are extracted industrially such as lead, tungsten, gold, tin, fluorspar, manganese, marble, copper and zinc. There are offshore gas deposits in the Atlantic Ocean that are planned to be extracted in the future. According to "The Diamond Investigation", a book about the global diamond market, from 1978, De Beers, the largest diamond company, bought most of the Namibian diamonds, and would continue to do so, because "whatever government eventually comes to power they will need this revenue to survive".
How much revenue does mining provide Namibia?

One of the more notable applications of printing technology was the chao, the paper money of the Yuan. Chao were made from the bark of mulberry trees. The Yuan government used woodblocks to print paper money, but switched to bronze plates in 1275. The Mongols experimented with establishing the Chinese-style paper monetary system in Mongol-controlled territories outside of China. The Yuan minister Bolad was sent to Iran, where he explained Yuan paper money to the Il-khanate court of Gaykhatu. The Il-khanate government issued paper money in 1294, but public distrust of the exotic new currency doomed the experiment.
What was the Yuan's paper money called?

The term middle east as a noun and adjective was common in the 19th century in nearly every context except diplomacy and archaeology. An uncountable number of places appear to have had their middle easts from gardens to regions, including the United States. The innovation of the term "Near East" to mean the holdings of the Ottoman Empire as early as the Crimean War had left a geographical gap. The East Indies, or "Far East," derived ultimately from Ptolemy's "India Beyond the Ganges." The Ottoman Empire ended at the eastern border of Iraq. "India This Side of the Ganges" and Iran had been omitted. The archaeologists counted Iran as "the Near East" because Old Persian cuneiform had been found there. This usage did not sit well with the diplomats; India was left in an equivocal state. They needed a regional term.

When was the term middle east common as a noun and adjective?