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.

Input: Consider Input: The diversion of heavier bombers to the Balkans meant that the crews and units left behind were asked to fly two or three sorties per night. Bombers were noisy, cold, and vibrated badly. Added to the tension of the mission which exhausted and drained crews, tiredness caught up with and killed many. In one incident on 28/29 April, Peter Stahl of KG 30 was flying on his 50th mission. He fell asleep at the controls of his Ju 88 and woke up to discover the entire crew asleep. He roused them, ensured they took oxygen and Dextro-Energen tablets, then completed the mission.

Output: How many sorties a night were crews asked to fly?


Input: Consider Input: Many ancient civilizations alloyed metals for purely aesthetic purposes. In ancient Egypt and Mycenae, gold was often alloyed with copper to produce red-gold, or iron to produce a bright burgundy-gold. Gold was often found alloyed with silver or other metals to produce various types of colored gold. These metals were also used to strengthen each other, for more practical purposes. Copper was often added to silver to make sterling silver, increasing its strength for use in dishes, silverware, and other practical items. Quite often, precious metals were alloyed with less valuable substances as a means to deceive buyers. Around 250 BC, Archimedes was commissioned by the king to find a way to check the purity of the gold in a crown, leading to the famous bath-house shouting of "Eureka!" upon the discovery of Archimedes' principle.

Output: Ancient civilizations often alloyed metals for what reason?


Input: Consider Input: The Roman Catholic Church celebrates his feast day not on the date of his death, June 3, as is usual, nor even on the day of his papal inauguration (as is sometimes done with Popes who are Saints, such as with John Paul II) but on 11 October, the day of the first session of the Second Vatican Council. This is understandable, since he was the one who had had the idea for it and had convened it. On Thursday, 11 September 2014, Pope Francis added his optional memorial to the worldwide General Roman Calendar of saints' feast days, in response to global requests. He is commemorated on the date of his death, 3 June, by the Evangelical Lutheran Church in America and on the following day, 4 June, by the Anglican Church of Canada and the Episcopal Church (United States).


Output: When is his feast day celebrated?