Problem: Capacitor:

Charles Pollak (born Karol Pollak), the inventor of the first electrolytic capacitors, found out that the oxide layer on an aluminum anode remained stable in a neutral or alkaline electrolyte, even when the power was switched off. In 1896 he filed a patent for an "Electric liquid capacitor with aluminum electrodes." Solid electrolyte tantalum capacitors were invented by Bell Laboratories in the early 1950s as a miniaturized and more reliable low-voltage support capacitor to complement their newly invented transistor.

In what year was the patent filed for an electric liquid capacitor?
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A: In 1896

Problem: Arsenal reached the final of the 2007 and 2011 League Cups, losing 21 to Chelsea and Birmingham City respectively. The club had not gained a major trophy since the 2005 FA Cup until 17 May 2014, when Arsenal beat Hull City in the 2014 FA Cup Final, coming back from a 20 deficit to win the match 32. This qualified them for the 2014 FA Community Shield where they would play Premier League champions Manchester City. They recorded a resounding 30 win in the game, winning their second trophy in three months. Nine months after their Community Shield triumph, Arsenal appeared in the FA Cup final for the second year in a row, thrashing Aston Villa 40 in the final and becoming the most successful club in the tournament's history with 12 titles. On 2 August 2015, Arsenal beat Chelsea 10 at Wembley Stadium to retain the Community Shield and earn their 14th Community Shield title.
Who did Arsenal win the 2005 FA Cup over?
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Answer: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
On February 29, 2012, Microsoft released Windows 8 Consumer Preview, the beta version of Windows 8, build 8250. Alongside other changes, the build removed the Start button from the taskbar for the first time since its debut on Windows 95; according to Windows manager Chaitanya Sareen, the Start button was removed to reflect their view that on Windows 8, the desktop was an "app" itself, and not the primary interface of the operating system. Windows president Steven Sinofsky said more than 100,000 changes had been made since the developer version went public. The day after its release, Windows 8 Consumer Preview had been downloaded over one million times. Like the Developer Preview, the Consumer Preview expired on January 15, 2013.
When was the beta version of Windows 9 made available to the public?
A: unanswerable

Context and question: Ibn Sina subsequently settled at Rey, in the vicinity of modern Tehran, the home town of Rhazes; where Majd Addaula, a son of the last Buwayhid emir, was nominal ruler under the regency of his mother (Seyyedeh Khatun). About thirty of Ibn Sina's shorter works are said to have been composed in Rey. Constant feuds which raged between the regent and her second son, Shams al-Daula, however, compelled the scholar to quit the place. After a brief sojourn at Qazvin he passed southwards to Hamadan where Shams al-Daula, another Buwayhid emir, had established himself. At first, Ibn Sina entered into the service of a high-born lady; but the emir, hearing of his arrival, called him in as medical attendant, and sent him back with presents to his dwelling. Ibn Sina was even raised to the office of vizier. The emir decreed that he should be banished from the country. Ibn Sina, however, remained hidden for forty days in sheikh Ahmed Fadhel's house, until a fresh attack of illness induced the emir to restore him to his post. Even during this perturbed time, Ibn Sina persevered with his studies and teaching. Every evening, extracts from his great works, the Canon and the Sanatio, were dictated and explained to his pupils. On the death of the emir, Ibn Sina ceased to be vizier and hid himself in the house of an apothecary, where, with intense assiduity, he continued the composition of his works.
Who's death made Ibn Sani a vizier?
Answer: unanswerable

Question: In 1980, the Soviet Union, which then ruled his birthplace Bukhara, celebrated the thousandth anniversary of Avicenna's birth by circulating various commemorative stamps with artistic illustrations, and by erecting a bust of Avicenna based on anthropological research by Soviet scholars.[citation needed] Near his birthplace in Qishlak Afshona, some 25 km (16 mi) north of Bukhara, a training college for medical staff has been named for him.[year needed] On the grounds is a museum dedicated to his life, times and work.[citation needed]
Is there an answer to this question: In 1980, how many years had it been since Avicenna's death?

Answer: unanswerable

Question: After 12 years as commissioner of the AFL, David Baker retired unexpectedly on July 25, 2008, just two days before ArenaBowl XXII; deputy commissioner Ed Policy was named interim commissioner until Baker's replacement was found. Baker explained, "When I took over as commissioner, I thought it would be for one year. It turned into 12. But now it's time."
Is there an answer to this question: On what date did Baker step down as commissioner of the AFL?

Answer:
July 25, 2008