Problem: Videoconferencing:

This technique was very expensive, though, and could not be used for applications such as telemedicine, distance education, and business meetings. Attempts at using normal telephony networks to transmit slow-scan video, such as the first systems developed by AT&T Corporation, first researched in the 1950s, failed mostly due to the poor picture quality and the lack of efficient video compression techniques. The greater 1 MHz bandwidth and 6 Mbit/s bit rate of the Picturephone in the 1970s also did not achieve commercial success, mostly due to its high cost, but also due to a lack of network effect with only a few hundred Picturephones in the world, users had extremely few contacts they could actually call to, and interoperability with other videophone systems would not exist for decades.

In what area could business meetings not be used?
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A: unanswerable

Problem: The Chalukya Empire (Kannada: [taukj]) was an Indian royal dynasty that ruled large parts of southern and central India between the 6th and the 12th centuries. During this period, they ruled as three related yet individual dynasties. The earliest dynasty, known as the "Badami Chalukyas", ruled from Vatapi (modern Badami) from the middle of the 6th century. The Badami Chalukyas began to assert their independence at the decline of the Kadamba kingdom of Banavasi and rapidly rose to prominence during the reign of Pulakeshin II. The rule of the Chalukyas marks an important milestone in the history of South India and a golden age in the history of Karnataka. The political atmosphere in South India shifted from smaller kingdoms to large empires with the ascendancy of Badami Chalukyas. A Southern India-based kingdom took control and consolidated the entire region between the Kaveri and the Narmada rivers. The rise of this empire saw the birth of efficient administration, overseas trade and commerce and the development of new style of architecture called "Chalukyan architecture". The Chalukya dynasty ruled parts of southern and central India from Badami in Karnataka between 550 and 750, and then again from Kalyani between 970 and 1190.
When did the Chalukya Empire rule?
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Answer: 6th and the 12th centuries

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Although not specifically prepared to conduct independent strategic air operations against an opponent, the Luftwaffe was expected to do so over Britain. From July until September 1940 the Luftwaffe attacked RAF Fighter Command to gain air superiority as a prelude to invasion. This involved the bombing of English Channel convoys, ports, and RAF airfields and supporting industries. Destroying RAF Fighter Command would allow the Germans to gain control of the skies over the invasion area. It was supposed that Bomber Command, RAF Coastal Command and the Royal Navy could not operate under conditions of German air superiority.
Which Navy was assumed not to be able to operate under German air superiority?
A: Royal

Context and question: Elizabeth's many historic visits and meetings include a state visit to the Republic of Ireland and reciprocal visits to and from the Pope. She has seen major constitutional changes, such as devolution in the United Kingdom, Canadian patriation, and the decolonisation of Africa. She has also reigned through various wars and conflicts involving many of her realms. She is the world's oldest reigning monarch as well as Britain's longest-lived. In 2015, she surpassed the reign of her great-great-grandmother, Queen Victoria, to become the longest-reigning British head of state and the longest-reigning queen regnant in world history.
When was the last year the Pope traveled to England to meet Elizabeth?
Answer: unanswerable

Question: From the mid-1950s through the 1960s, in the U.S. the common home record player or "stereo" (after the introduction of stereo recording) would typically have had these features: a three- or four-speed player (78, 45, 33 13, and sometimes 16 23 rpm); with changer, a tall spindle that would hold several records and automatically drop a new record on top of the previous one when it had finished playing, a combination cartridge with both 78 and microgroove styli and a way to flip between the two; and some kind of adapter for playing the 45s with their larger center hole. The adapter could be a small solid circle that fit onto the bottom of the spindle (meaning only one 45 could be played at a time) or a larger adaptor that fit over the entire spindle, permitting a stack of 45s to be played.
Is there an answer to this question: What feature of 45s required an adapter in most home stereos?

Answer: larger center hole.

QUES: Evidence of Han-era mechanical engineering comes largely from the choice observational writings of sometimes disinterested Confucian scholars. Professional artisan-engineers (jiang ) did not leave behind detailed records of their work. Han scholars, who often had little or no expertise in mechanical engineering, sometimes provided insufficient information on the various technologies they described. Nevertheless, some Han literary sources provide crucial information. For example, in 15 BC the philosopher Yang Xiong described the invention of the belt drive for a quilling machine, which was of great importance to early textile manufacturing. The inventions of the artisan-engineer Ding Huan () are mentioned in the Miscellaneous Notes on the Western Capital. Around 180 AD, Ding created a manually operated rotary fan used for air conditioning within palace buildings. Ding also used gimbals as pivotal supports for one of his incense burners and invented the world's first known zoetrope lamp.

Which engineer was responsible for first inventing the zoetrope lamp?
What is the answer?
ANS:
Ding Huan