This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

[EX Q]: Passage: Energy gives rise to weight when it is trapped in a system with zero momentum, where it can be weighed. It is also equivalent to mass, and this mass is always associated with it. Mass is also equivalent to a certain amount of energy, and likewise always appears associated with it, as described in mass-energy equivalence. The formula E = mc², derived by Albert Einstein (1905) quantifies the relationship between rest-mass and rest-energy within the concept of special relativity. In different theoretical frameworks, similar formulas were derived by J. J. Thomson (1881), Henri Poincaré (1900), Friedrich Hasenöhrl (1904) and others (see Mass-energy equivalence#History for further information). Question: In what year did Einstein create E = mc2?
[EX A]: 1905

[EX Q]: Passage: By 1900, 7,531 people lived in the city. The population increased gradually to 13,913 in 1910. At about this time, the U.S. Veterans Administration had begun construction on the present Veterans Hospital. Many veterans who had been gassed in World War I and were in need of respiratory therapy began coming to Tucson after the war, due to the clean dry air. Over the following years the city continued to grow, with the population increasing to 20,292 in 1920 and 36,818 in 1940. In 2006 the population of Pima County, in which Tucson is located, passed one million while the City of Tucson's population was 535,000. Question: What was Tucson's population in 2006?
[EX A]: 535,000

[EX Q]: Passage:  Vietnam: The event was held in Ho Chi Minh City on April 29. Some 60 torchbearers carried the torch from the downtown Opera House to the Military Zone 7 Competition Hall stadium near Tan Son Nhat International Airport along an undisclosed route. Vietnam is involved in a territorial dispute with China (and other countries) for sovereignty of the Spratly and Paracel Islands; tensions have risen recently[when?] following reports that the Chinese government had established a county-level city named Sansha in the disputed territories, resulting in anti-Chinese demonstrations in December 2007 in Hanoi and Ho Chi Minh City. However to sustain its relationship with China the Vietnamese government has actively sought to head off protests during the torch relay, with Prime Minister Nguyễn Tấn Dũng warning government agencies that "hostile forces" may try to disrupt the torch relay. Question: When did the torch arrive in Vietnam?
[EX A]:
April 29