Problem: Extract the answer to the question from the following context. Question: The Catholic church's unity would be what to Luther? Context: Contrary to how the Protestant Reformers were often characterized, the concept of a catholic or universal Church was not brushed aside during the Protestant Reformation. On the contrary, the visible unity of the catholic or universal church was seen by the Protestant reformers as an important and essential doctrine of the Reformation. The Magisterial reformers, such as Martin Luther, John Calvin, and Huldrych Zwingli, believed that they were reforming the Roman Catholic Church, which they viewed as having become corrupted. Each of them took very seriously the charges of schism and innovation, denying these charges and maintaining that it was the Roman Catholic Church that had left them. In order to justify their departure from the Roman Catholic Church, Protestants often posited a new argument, saying that there was no real visible Church with divine authority, only a spiritual, invisible, and hidden churchthis notion began in the early days of the Protestant Reformation.

A: an important and essential doctrine of the Reformation

Problem: Extract the answer to the question from the following context. Question: What is approximately equal to 3.14159? Context: Three Han mathematical treatises still exist. These are the Book on Numbers and Computation, the Arithmetical Classic of the Gnomon and the Circular Paths of Heaven and the Nine Chapters on the Mathematical Art. Han-era mathematical achievements include solving problems with right-angle triangles, square roots, cube roots, and matrix methods, finding more accurate approximations for pi, providing mathematical proof of the Pythagorean theorem, use of the decimal fraction, Gaussian elimination to solve linear equations, and continued fractions to find the roots of equations.

A: pi

Problem: Extract the answer to the question from the following context. Question: Which of the following is not an advantage of remote diagnosing: saving lives, videoconferencing, or efficient use of health care money? Context: Videoconferencing is a highly useful technology for real-time telemedicine and telenursing applications, such as diagnosis, consulting, transmission of medical images, etc... With videoconferencing, patients may contact nurses and physicians in emergency or routine situations; physicians and other paramedical professionals can discuss cases across large distances. Rural areas can use this technology for diagnostic purposes, thus saving lives and making more efficient use of health care money. For example, a rural medical center in Ohio, United States, used videoconferencing to successfully cut the number of transfers of sick infants to a hospital 70 miles (110 km) away. This had previously cost nearly $10,000 per transfer.

A: videoconferencing

Problem: Extract the answer to the question from the following context. Question: Which of the following happened second, the Korean war or a centuries-long golden age? Context: Zhejiang, as the heartland of the Jiangnan (Yangtze River Delta), remained the wealthiest area during the Six Dynasties (220 or 222589), Sui, and Tang. After being incorporated into the Sui dynasty, its economic richness was used for the Sui dynasty's ambitions to expand north and south, particularly into Korea and Vietnam. The plan led the Sui dynasty to restore and expand the network which became the Grand Canal of China. The Canal regularly transported grains and resources from Zhejiang, through its metropolitan center Hangzhou (and its hinterland along both the Zhe River and the shores of Hangzhou Bay), and from Suzhou, and thence to the North China Plain. The debacle of the Korean war led to Sui's overthrow by the Tang, who then presided over a centuries-long golden age for the country. Zhejiang was an important economic center of the empire's Jiangnan East Circuit and was considered particularly prosperous. Throughout the Tang dynasty, The Grand Canal had remained effective, transporting grains and material resources to North China plain and metropolitan centers of the empire. As the Tang Dynasty disintegrated, Zhejiang constituted most of the territory of the regional kingdom of Wuyue.

A:
centuries-long golden age