Problem: Translation:

Comparison of a back-translation with the original text is sometimes used as a check on the accuracy of the original translation, much as the accuracy of a mathematical operation is sometimes checked by reversing the operation. But the results of such reverse-translation operations, while useful as approximate checks, are not always precisely reliable. Back-translation must in general be less accurate than back-calculation because linguistic symbols (words) are often ambiguous, whereas mathematical symbols are intentionally unequivocal.

What operations are always reliable?
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A: unanswerable

Problem: 2008 Sichuan earthquake:

In 2002, Chinese geologist Chen Xuezhong published a Seismic Risk Analysis study in which he came to the conclusion that beginning with 2003, attention should be paid to the possibility of an earthquake with a magnitude of over 7.0 occurring in Sichuan region. He based his study on statistical correlation. That Sichuan is a seismically active area has been discussed for years prior to the quake, though few studies point to a specific date and time.

Who published the Seismic Risk Analysis?
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A: Chen Xuezhong

Problem: Modern history:

In Britain's "imperial century", victory over Napoleon left Britain without any serious international rival, other than Russia in central Asia. Unchallenged at sea, Britain adopted the role of global policeman, a state of affairs later known as the Pax Britannica, and a foreign policy of "splendid isolation". Alongside the formal control it exerted over its own colonies, Britain's dominant position in world trade meant that it effectively controlled the economies of many nominally independent countries, such as China, Argentina and Siam, which has been generally characterized as "informal empire". Of note during this time was the Anglo-Zulu War, which was fought in 1879 between the British Empire and the Zulu Empire.

Why did Britain adopt the role of Global Policemen?
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A: Unchallenged at sea

Problem: Affirmative action in the United States:

In June 1963, President Kennedy continued his policy of affirmative action by issuing another mandate, Executive Order 11114. The order supplemented to his previous 1961 executive order declaring it was the "policy of the United States to encourage by affirmative action the elimination of discrimination in employment".:72 Through this order, all federal funds, such as "grants, loans, unions and employers who accepted taxpayer funds, and other forms of financial assistance to state and local governments," were forced to comply to the government's policies on affirmative action in employment practices.:72

When did President Kennedy issue Executive Order 11114?
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A:
June 1963