Problem: In 1571 the Crimean Khan burned Moscow. He tried again the next year and was defeated. Another large raid failed in 1591. The raiding area may have moved slightly south and east. Attacks east of Ryazan are mentioned more frequently. After 1585 forts were built far to the south to block the Muravsky Trail, but these had no visible effect in this period. Raids on Poland are mentioned under 1577, 1584 and 1595.
Answer this question based on the article: How many years spanned from when forts were built far to the south to block the Muravsky Trail to Another large raid failed?
A: 6

Problem: In late 1920, the Persian Soviet Socialist Republic in Rasht was preparing to march on Tehran with "a guerrilla force of 1,500 Jangalis, Kurds, Armenians and Azerbaijanis", reinforced by the Bolsheviks' Red Army. This fact, along with various other disorders, mutinies and unrest in the country created "an acute political crisis in the capital." By 1921, the ruling Qajar dynasty of Persia had become corrupt and inefficient. The oil-rich nation was somewhat reliant on the nations of Britain and Russia for military and economic support. Civil wars earlier in the decade had threatened the government, and the only regular military force at the time was the Cossack Brigade. The Qajar shah in 1921 was Ahmad, who had been crowned at the age of eleven. He was considered to be a weak, incompetent ruler, especially after British, Russian and Ottoman occupations of Persia during World War I. In 1911, when the capital city, Tehran, had been seized by the Russians, armed Bakhtiaris tribemen, rather than Iranian regular troops, expelled the invaders. This further diminished the government's reputation, rendering it almost powerless in time of war. Britain, which played a major role in Persia, was dismayed by the Qajar government's inability to rule efficiently. This inefficiency was the background of a power struggle between Britain and Russia, each nation hoping to control Persia. On 14 January 1921, the British General Ironside chose to promote Reza Khan, who had been leading the Tabriz battalion, to lead the entire brigade. About a month later, under British direction, Reza Khan's 3,000-4,000 strong detachment of the Cossack Brigade reached Tehran.
Answer this question based on the article: What countries corruption caused an acute political crisis?
A: Persia

Problem: The 1970s saw a number of new models added to the Buick lineup including the Estate Wagon as its own model in 1970, Buick Centurion in 1971, Buick Apollo in 1973, and Buick Skyhawk in 1975. 1975 also saw the first appearance of the "Buick Park Avenue" nameplate for Buick as a trim/option package on the Electra 225 Limited. A Buick Century paced the Indianapolis 500 race not once but twice in the mid 1970s. For 1976, Buick began selling rebadged Isuzu Geminis as Opels to replace the Opel Kadett models it had previously marketed. The following year, Electra 225 and LeSabre were redesigned and downsized and the Buick brand saw its best model year sales to date with 773,313 vehicles sold. 1978 marked Buicks 75th anniversary and welcomed a redesigned Century as well as a redesigned Regal coupe which was now available with a turbocharged Buick V6 engine engine. Buick model year sales broke another record in 1978 with 795,316 vehicles sold. For 1979, the Riviera was redesigned; Riviera S-Type was named Motor Trend Car of the Year.
Answer this question based on the article: How many models were redesigned in 1978?
A:
2