Problem: Anti-aircraft warfare:

AA gunnery was a difficult business. The problem was of successfully aiming a shell to burst close to its target's future position, with various factors affecting the shells' predicted trajectory. This was called deflection gun-laying, 'off-set' angles for range and elevation were set on the gunsight and updated as their target moved. In this method when the sights were on the target, the barrel was pointed at the target's future position. Range and height of the target determined fuse length. The difficulties increased as aircraft performance improved.

What was the problem with AA gunnery?
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A: successfully aiming a shell to burst close to its target's future position


Problem: Studies conducted on both animals and humans show major bidirectional relationships between the circadian system and abusive drugs. It is indicated that these abusive drugs affect the central circadian pacemaker. Individuals suffering from substance abuse display disrupted rhythms. These disrupted rhythms can increase the risk for substance abuse and relapse. It is possible that genetic and/or environmental disturbances to the normal sleep and wake cycle can increase the susceptibility to addiction.
What studies show a minor relationship between the circadian system and drug abuse?
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Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
As computers grew in speed and capability, a number of general-purpose database systems emerged; by the mid-1960s a number of such systems had come into commercial use. Interest in a standard began to grow, and Charles Bachman, author of one such product, the Integrated Data Store (IDS), founded the "Database Task Group" within CODASYL, the group responsible for the creation and standardization of COBOL. In 1971 the Database Task Group delivered their standard, which generally became known as the "CODASYL approach", and soon a number of commercial products based on this approach entered the market.
What group destroyed COBOL?
A: unanswerable


Context and question: New developments in Judaism often transcend differences in religious practice between Ashkenazi and Sephardic Jews. In North American cities, social trends such as the chavurah movement, and the emergence of "post-denominational Judaism" often bring together younger Jews of diverse ethnic backgrounds. In recent years, there has been increased interest in Kabbalah, which many Ashkenazi Jews study outside of the Yeshiva framework. Another trend is the new popularity of ecstatic worship in the Jewish Renewal movement and the Carlebach style minyan, both of which are nominally of Ashkenazi origin.
What two things were mentioned as contributing to bringing younger Jews together in North American cities?
Answer: social trends such as the chavurah movement, and the emergence of "post-denominational Judaism"


Question: In February 2015, YouTube announced the launch of a new app specifically for use by children visiting the site, called YouTube Kids. It allows parental controls and restrictions on who can upload content, and is available for both Android and iOS devices. Later on August 26, 2015, YouTube Gaming was launched, a platform for video gaming enthusiasts intended to compete with Twitch.tv. 2015 also saw the announcement of a premium YouTube service titled YouTube Red, which provides users with both ad-free content as well as the ability to download videos among other features.
Is there an answer to this question: what was the name of the new app youtube launched?

Answer: YouTube Kids


QUES: Iran received access to the Internet in 1993. According to 2014 census, around 40% of the population of Iran are Internet users. Iran ranks 24th among countries by number of Internet users. According to the statistics provided by the web information company of Alexa, Google Search and Yahoo! are the most used search engines in Iran. Over 80% of the users of Telegram, a cloud-based instant messaging service, are from Iran. Instagram is the most popular online social networking service in Iran. Direct access to Facebook has been blocked in Iran since the 2009 Iranian presidential election protests, due to organization of the opposition movements on the website; but however, Facebook has around 12 to 17 million users in Iran who are using virtual private networks and proxy servers to access the website. Around 90% of Iran's e-commerce takes place on the Iranian online store of Digikala, which has around 750,000 visitors per day and more than 2.3 million subscribers. Digikala is the most visited online store in the Middle East, and ranks 4th among the most visited websites in Iran.

What percentage of cloud-based instant messaging platform Telegram's users are from Iran? 
What is the answer?
ANS:
Over 80%