instruction:
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.
question:
The Prussian Army, under the terms of the armistice, held a brief victory parade in Paris on 17 February; the city was silent and draped with black and the Germans quickly withdrew. Bismarck honoured the armistice, by allowing train loads of food into Paris and withdrawing Prussian forces to the east of the city, prior to a full withdrawal once France agreed to pay a five billion franc war indemnity. At the same time, Prussian forces were concentrated in the provinces of Alsace and Lorraine. An exodus occurred from Paris as some 200,000 people, predominantly middle-class, went to the countryside.
answer:
What did the Prussian Army hold in Paris on 17 February?

question:
With the defeat of Marshal Bazaine's Army of the Rhine at Gravelotte, the French were forced to retire to Metz, where they were besieged by over 150,000 Prussian troops of the First and Second Armies. Napoleon III and MacMahon formed the new French Army of Chalons, to march on to Metz to rescue Bazaine. Napoleon III personally led the army with Marshal MacMahon in attendance. The Army of Chalons marched northeast towards the Belgian border to avoid the Prussians before striking south to link up with Bazaine. The Prussians, under the command of Field Marshal Count Helmuth von Moltke, took advantage of this maneuver to catch the French in a pincer grip. He left the Prussian First and Second Armies besieging Metz, except three corps detached to form the Army of the Meuse under the Crown Prince of Saxony. With this army and the Prussian Third Army, Moltke marched northward and caught up with the French at Beaumont on 30 August. After a sharp fight in which they lost 5,000 men and 40 cannons, the French withdrew toward Sedan. Having reformed in the town, the Army of Chalons was immediately isolated by the converging Prussian armies. Napoleon III ordered the army to break out of the encirclement immediately. With MacMahon wounded on the previous day, General Auguste Ducrot took command of the French troops in the field.
answer:
What factor forced the French to retreat to Metz?

question:
The modern Slavic peoples carry a variety of mitochondrial DNA haplogroups and Y-chromosome DNA haplogroups. Yet two paternal haplogroups predominate: R1a1a [M17] and I2a2a [L69.2=T/S163.2]. The frequency of Haplogroup R1a ranges from 63.39% in the Sorbs, through 56.4% in Poland, 54% in Ukraine, 52% in Russia, Belarus, to 15.2% in Republic of Macedonia, 14.7% in Bulgaria and 12.1% in Herzegovina. The correlation between R1a1a [M17] and the speakers of Indo-European languages, particularly those of Eastern Europe (Russian) and Central and Southern Asia, was noticed in the late 1990s. From this Spencer Wells and colleagues, following the Kurgan hypothesis, deduced that R1a1a arose on the Pontic-Caspian steppe.
answer:
What two DNA haplogroups predominate in modern Slavic peoples?