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.
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Question: During the years 1940-1955, the rate of decline in the U.S. death rate accelerated from 2% per year to 8% per year, then returned to the historical rate of 2% per year. The dramatic decline in the immediate post-war years has been attributed to the rapid development of new treatments and vaccines for infectious disease that occurred during these years. Vaccine development continued to accelerate, with the most notable achievement of the period being Jonas Salk's 1954 development of the polio vaccine under the funding of the non-profit National Foundation for Infantile Paralysis. The vaccine process was never patented, but was instead given to pharmaceutical companies to manufacture as a low-cost generic. In 1960 Maurice Hilleman of Merck Sharp & Dohme identified the SV40 virus, which was later shown to cause tumors in many mammalian species. It was later determined that SV40 was present as a contaminant in polio vaccine lots that had been administered to 90% of the children in the United States. The contamination appears to have originated both in the original cell stock and in monkey tissue used for production. In 2004 the United States Cancer Institute announced that it had concluded that SV40 is not associated with cancer in people.

Answer: When was the Polio vaccine created?


Question: Following the 11 September 2001 attacks, former President of Pakistan Pervez Musharraf sided with the U.S. against the Taliban government in Afghanistan after an ultimatum by then U.S. President George W. Bush. Musharraf agreed to give the U.S. the use of three airbases for Operation Enduring Freedom. United States Secretary of State Colin Powell and other U.S. administration officials met with Musharraf. On 19 September 2001, Musharraf addressed the people of Pakistan and stated that, while he opposed military tactics against the Taliban, Pakistan risked being endangered by an alliance of India and the U.S. if it did not cooperate. In 2006, Musharraf testified that this stance was pressured by threats from the U.S., and revealed in his memoirs that he had "war-gamed" the United States as an adversary and decided that it would end in a loss for Pakistan.

Answer: Which Pakistan president supported the US attacking the Taliban?


Question: The distinctive characteristic of French cathedrals, and those in Germany and Belgium that were strongly influenced by them, is their height and their impression of verticality. Each French cathedral tends to be stylistically unified in appearance when compared with an English cathedral where there is great diversity in almost every building. They are compact, with slight or no projection of the transepts and subsidiary chapels. The west fronts are highly consistent, having three portals surmounted by a rose window, and two large towers. Sometimes there are additional towers on the transept ends. The east end is polygonal with ambulatory and sometimes a chevette of radiating chapels. In the south of France, many of the major churches are without transepts and some are without aisles.

Answer:
What is the distinguiushing visual design feature of French cathedrals?