TASK DEFINITION: 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.
PROBLEM: Up to the 1990s, the Federal District was the most populous federal entity in Mexico, but since then its population has remained stable at around 8.7 million. The growth of the city has extended beyond the limits of the Federal District to 59 municipalities of the state of Mexico and 1 in the state of Hidalgo. With a population of approximately 19.8 million inhabitants (2008), it is one of the most populous conurbations in the world. Nonetheless, the annual rate of growth of the Metropolitan Area of Mexico City is much lower than that of other large urban agglomerations in Mexico, a phenomenon most likely attributable to the environmental policy of decentralization. The net migration rate of the Federal District from 1995 to 2000 was negative.

SOLUTION: How many people live in the Federal District? 

PROBLEM: Kublai's government after 1262 was a compromise between preserving Mongol interests in China and satisfying the demands of his Chinese subjects. He instituted the reforms proposed by his Chinese advisers by centralizing the bureaucracy, expanding the circulation of paper money, and maintaining the traditional monopolies on salt and iron. He restored the Imperial Secretariat and left the local administrative structure of past Chinese dynasties unchanged. However, Kublai rejected plans to revive the Confucian imperial examinations and divided Yuan society into three, later four, classes with the Han Chinese occupying the lowest rank. Kublai's Chinese advisers still wielded significant power in the government, but their official rank was nebulous.

SOLUTION: What did Kublai's government have to balance between?

PROBLEM: General Secretary and President Hu Jintao announced that the disaster response would be rapid. Just 90 minutes after the earthquake, Premier Wen Jiabao, who has an academic background in geomechanics, flew to the earthquake area to oversee the rescue work. Soon afterward, the Ministry of Health said that it had sent ten emergency medical teams to Wenchuan County. On the same day, the Chengdu Military Region Command dispatched 50,000 troops and armed police to help with disaster relief work in Wenchuan County. However, due to the rough terrain and close proximity of the quake's epicenter, the soldiers found it very difficult to get help to the rural regions of the province.

SOLUTION:
Who flew to the earthquake area 90 minutes after it hit?