Problem: Nanjing:

Over two centuries after the removal of the capital to Beijing, Nanjing was destined to become the capital of a Ming emperor one more time. After the fall of Beijing to Li Zicheng's rebel forces and then to the Manchu-led Qing dynasty in the spring of 1644, the Ming prince Zhu Yousong was enthroned in Nanjing in June 1644 as the Hongguang Emperor. His short reign was described by later historians as the first reign of the so-called Southern Ming dynasty.

When did Beijing lose to Li Zicheng's rebel forces and the Manchu-led Qing dynasty?
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A: 1644

Problem: In 1654, Otto von Guericke invented the first vacuum pump and conducted his famous Magdeburg hemispheres experiment, showing that teams of horses could not separate two hemispheres from which the air had been partially evacuated. Robert Boyle improved Guericke's design and with the help of Robert Hooke further developed vacuum pump technology. Thereafter, research into the partial vacuum lapsed until 1850 when August Toepler invented the Toepler Pump and Heinrich Geissler invented the mercury displacement pump in 1855, achieving a partial vacuum of about 10 Pa (0.1 Torr). A number of electrical properties become observable at this vacuum level, which renewed interest in further research.
What did Heinrich Geissler help Otto von Guericke further develop?
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Answer: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Alexandria was the most important trade center in the whole empire during Athanasius's boyhood. Intellectually, morally, and politicallyit epitomized the ethnically diverse Graeco-Roman world, even more than Rome or Constantinople, Antioch or Marseilles. Its famous catechetical school, while sacrificing none of its famous passion for orthodoxy since the days of Pantaenus, Clement of Alexandria, Origen of Alexandria, Dionysius and Theognostus, had begun to take on an almost secular character in the comprehensiveness of its interests, and had counted influential pagans among its serious auditors.
What was the name of the city where Athanasius went to catechetical school?
A: unanswerable

Context and question: The use of the term for the Iranian language family was introduced in 1836 by Christian Lassen. Robert Needham Cust used the term Irano-Aryan in 1878, and Orientalists such as George Abraham Grierson and Max Muller contrasted Irano-Aryan (Iranian) and Indo-Aryan (Indic). Some recent scholarship, primarily in German, has revived this convention.
What scholars have revived the term Irano-Aryan
Answer: unanswerable

Question: Materialism developed, possibly independently, in several geographically separated regions of Eurasia during what Karl Jaspers termed the Axial Age (approximately 800 to 200 BC).
Is there an answer to this question: When was Karl Jaspers born?

Answer: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Located in the American South, Houston is a diverse city with a large and growing international community. The metropolitan area is home to an estimated 1.1 million (21.4 percent) residents who were born outside the United States, with nearly two-thirds of the area's foreign-born population from south of the United StatesMexico border. Additionally, more than one in five foreign-born residents are from Asia. The city is home to the nation's third-largest concentration of consular offices, representing 86 countries.
In what part of the United States is Houston located?
A:
South