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: Devonport Dockyard is the UK's only naval base that refits nuclear submarines and the Navy estimates that the Dockyard generates about 10% of Plymouth's income. Plymouth has the largest cluster of marine and maritime businesses in the south west with 270 firms operating within the sector. Other substantial employers include the university with almost 3,000 staff, as well as the Tamar Science Park employing 500 people in 50 companies. Several employers have chosen to locate their headquarters in Plymouth, including Hemsley Fraser.

Answer: About what percentage of Plymouth's income comes from the Dockyard?


Question: Roofs are traditionally constructed from Alpine rocks such as pieces of schist, gneiss or slate. Such chalets are typically found in the higher parts of the valleys, as in the Maurienne valley in Savoy, where the amount of snow during the cold months is important. The inclination of the roof cannot exceed 40%, allowing the snow to stay on top, thereby functioning as insulation from the cold. In the lower areas where the forests are widespread, wooden tiles are traditionally used. Commonly made of Norway spruce, they are called "tavaillon". The Alpine regions are multicultural and linguistically diverse. Dialects are common, and vary from valley to valley and region to region. In the Slavic Alps alone 19 dialects have been identified. Some of the French dialects spoken in the French, Swiss and Italian alps of Aosta Valley derive from Arpitan, while the southern part of the western range is related to Old Provençal; the German dialects derive from Germanic tribal languages. Romansh, spoken by two percent of the population in southeast Switzerland, is an ancient Rhaeto-Romanic language derived from Latin, remnants of ancient Celtic languages and perhaps Etruscan.

Answer: What are roofs traditionally constructed from? 


Question: In early 1757, Frederick II again took the initiative by marching into the Kingdom of Bohemia, hoping to inflict a decisive defeat on Austrian forces. After winning the bloody Battle of Prague on 6 May 1757, in which both forces suffered major casualties, the Prussians forced the Austrians back into the fortifications of Prague. The Prussian army then laid siege to the city. Following the battle at Prague, Frederick took 5,000 troops from the siege at Prague and sent them to reinforce the 19,000-man army under the Duke of Brunswick-Bevern at Kolin in Bohemia. Austrian Marshal Daun arrived too late to participate in the battle of Prague, but picked up 16,000 men who had escaped from the battle. With this army he slowly moved to relieve Prague. The Prussian army was too weak to simultaneously besiege Prague and keep Daun away, and Frederick was forced to attack prepared positions. The resulting Battle of Kolin was a sharp defeat for Frederick, his first military defeat. His losses further forced him to lift the siege and withdraw from Bohemia altogether.

Answer:
Where did the Austrians retreat in May of 1757?