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: 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: Wu Chinese has a three-way distinction in stops and affricates: /p pʰ b/. In addition to aspirated and unaspirated consonants, there is a series of muddy consonants, like /b/. These are pronounced with slack or breathy voice: that is, they are weakly voiced. Muddy consonants as initial cause a syllable to be pronounced with low pitch or light (陽 yáng) tone.

Output: What has a three-way distinction in regards to stops and affricates?


Input: Consider Input: On 4 January 2016, Barcelona's transfer ban ended. The same day, they registered 77 players across all categories and ages, and both last summer signings Arda Turan and Aleix Vidal became eligible to play with the first team. On 10 February, qualifying for the sixth Copa del Rey final in the last eight seasons, Luis Enrique’s Barcelona broke the club's record of 28 consecutive games unbeaten in all competitions set by Guardiola’s team in the 2010–11 season, with a 1–1 draw with Valencia in the second leg of the 2015–16 Copa del Rey.


Output: How many players did Barcelona list on the day their transfer ban ended?