TASK DEFINITION: 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.
PROBLEM: The city has several federal facilities, including the John F. Kennedy Federal Office Building, the Thomas P. O'Neill Federal Building, the United States Court of Appeals for the First Circuit, the United States District Court for the District of Massachusetts, and the Federal Reserve Bank of Boston.

SOLUTION: Where is the John F kennedy Federal office building located?

PROBLEM: Imperial College Boat Club
The Imperial College Boat Club was founded on 12 December 1919. The Gold medal winning GB 8+ at the 2000 Sydney Olympics had been based at Imperial College's recently refurbished boathouse and included 3 alumni of the college along with their coach Martin McElroy. The club has been highly successful, with many wins at Henley Royal Regatta including most recently in 2013 with victory in The Prince Albert Challenge Cup event. The club has been home to numerous National Squad oarsmen and women and is open to all rowers not just students of Imperial College London.

SOLUTION: Which day was the Imperial College Boat Club formed on?

PROBLEM: The expansion of the Rus' put further military and economic pressure on the Khazars, depriving them of territory, tributaries, and trade. In around 890, Oleg waged an indecisive war in the lands of the lower Dniester and Dnieper rivers with the Tivertsi and the Ulichs, who were likely acting as vassals of the Magyars, blocking Rus' access to the Black Sea. In 894, the Magyars and Pechenegs were drawn into the wars between the Byzantines and the Bulgarian Empire. The Byzantines arranged for the Magyars to attack Bulgarian territory from the north, and Bulgaria in turn persuaded the Pechenegs to attack the Magyars from their rear. Boxed in, the Magyars were forced to migrate further west across the Carpathian Mountains into the Hungarian plain, depriving the Khazars of an important ally and a buffer from the Rus'. The migration of the Magyars allowed Rus' access to the Black Sea, and they soon launched excursions into Khazar territory along the sea coast, up the Don river, and into the lower Volga region. The Rus' were raiding and plundering into the Caspian Sea region from 864, with the first large-scale expedition in 913, when they extensively raided Baku, Gilan, Mazandaran and penetrated into the Caucasus.

SOLUTION:
What led to Khazar having to put more strain on its military?