Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Back in Warsaw that year, Chopin heard Niccolò Paganini play the violin, and composed a set of variations, Souvenir de Paganini. It may have been this experience which encouraged him to commence writing his first Études, (1829–32), exploring the capacities of his own instrument. On 11 August, three weeks after completing his studies at the Warsaw Conservatory, he made his debut in Vienna. He gave two piano concerts and received many favourable reviews—in addition to some commenting (in Chopin's own words) that he was "too delicate for those accustomed to the piano-bashing of local artists". In one of these concerts, he premiered his Variations on Là ci darem la mano, Op. 2 (variations on an aria from Mozart's opera Don Giovanni) for piano and orchestra. He returned to Warsaw in September 1829, where he premiered his Piano Concerto No. 2 in F minor, Op. 21 on 17 March 1830.
What piece did Chopin debut after returning to Warsaw?
A: Piano Concerto No. 2 in F minor, Op. 21

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
When Emperor Kammu moved the capital to Heian-kyō (Kyōto), which remained the imperial capital for the next 1,000 years, he did so not only to strengthen imperial authority but also to improve his seat of government geopolitically. Nara was abandoned after only 70 years in part due to the ascendancy of Dōkyō and the encroaching secular power of the Buddhist institutions there. Kyōto had good river access to the sea and could be reached by land routes from the eastern provinces. The early Heian period (784–967) continued Nara culture; the Heian capital was patterned on the Chinese Tang capital at Chang'an, as was Nara, but on a larger scale than Nara. Kammu endeavoured to improve the Tang-style administrative system which was in use. Known as the ritsuryō, this system attempted to recreate the Tang imperium in Japan, despite the "tremendous differences in the levels of development between the two countries". Despite the decline of the Taika-Taihō reforms, imperial government was vigorous during the early Heian period. Indeed, Kammu's avoidance of drastic reform decreased the intensity of political struggles, and he became recognized as one of Japan's most forceful emperors.
Why was Nara maintained as the capital for 70 years?
A: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Born in Bay City, Michigan, Madonna moved to New York City in 1977 to pursue a career in modern dance. After performing in the music groups Breakfast Club and Emmy, she signed with Sire Records (an auxiliary label of Warner Bros. Records) in 1982 and released her self-titled debut album the following year. She followed it with a series of commercially and critcally successful albums, including the Grammy Award winners Ray of Light (1998) and Confessions on a Dance Floor (2005). Throughout her career, Madonna has written and produced most of her songs, with many of them reaching number one on the record charts, including "Like a Virgin", "Into the Groove", "Papa Don't Preach", "Like a Prayer", "Vogue", "Frozen", "Music", "Hung Up", and "4 Minutes".
In which year did Madonna move to New York City?
A: 1977

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Hume divided all of human knowledge into two categories: relations of ideas and matters of fact (see also Kant's analytic-synthetic distinction). Mathematical and logical propositions (e.g. "that the square of the hypotenuse is equal to the sum of the squares of the two sides") are examples of the first, while propositions involving some contingent observation of the world (e.g. "the sun rises in the East") are examples of the second. All of people's "ideas", in turn, are derived from their "impressions". For Hume, an "impression" corresponds roughly with what we call a sensation. To remember or to imagine such impressions is to have an "idea". Ideas are therefore the faint copies of sensations.
What type of human knowledge is "the sun rises in the East"?
A:
matters of fact