Problem: Alexander Graham Bell:

On June 21, 1880, Bell's assistant transmitted a wireless voice telephone message a considerable distance, from the roof of the Franklin School in Washington, D.C., to Bell at the window of his laboratory, some 213 metres (700 ft) away, 19 years before the first voice radio transmissions.

Bell and his assistant first used their photophone on what date?
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A: June 21, 1880


Problem: Numerous live performance events dedicated to house music were founded during the course of the decade, including Shambhala Music Festival and major industry sponsored events like Miami's Winter Music Conference. The genre even gained popularity in the Middle East in cities such as Dubai & Abu Dhabi[citation needed] and at events like Creamfields.
Where did the Winter Music Conference take place? 
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Answer: Miami


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The administration of Lord North (1770–1782) tried to defeat the colonist rebellion by military force. British and American forces clashed in 1775 and, in 1776, came the American Declaration of Independence. Burke was appalled by celebrations in Britain of the defeat of the Americans at New York and Pennsylvania. He claimed the English national character was being changed by this authoritarianism. Burke wrote: "As to the good people of England, they seem to partake every day more and more of the Character of that administration which they have been induced to tolerate. I am satisfied, that within a few years there has been a great Change in the National Character. We seem no longer that eager, inquisitive, jealous, fiery people, which we have been formerly".
What did Burke claim authoritarianism was being changed by?
A: unanswerable


Context and question: Rapid increases in a number of commodity prices followed the collapse in the housing bubble. The price of oil nearly tripled from $50 to $147 from early 2007 to 2008, before plunging as the financial crisis began to take hold in late 2008. Experts debate the causes, with some attributing it to speculative flow of money from housing and other investments into commodities, some to monetary policy, and some to the increasing feeling of raw materials scarcity in a fast-growing world, leading to long positions taken on those markets, such as Chinese increasing presence in Africa. An increase in oil prices tends to divert a larger share of consumer spending into gasoline, which creates downward pressure on economic growth in oil importing countries, as wealth flows to oil-producing states. A pattern of spiking instability in the price of oil over the decade leading up to the price high of 2008 has been recently identified. The destabilizing effects of this price variance has been proposed as a contributory factor in the financial crisis.
Following the collapse in the housing bubble, what happened to a number of commodity prices?
Answer: Rapid increases


Question: Kerry and his second wife, Mozambican-born businesswoman and philanthropist Maria Teresa Thierstein Simões Ferreira (known as Teresa), the widow of Kerry's late Pennsylvania Republican Senate colleague Henry John Heinz III, were introduced to each other by Heinz at an Earth Day rally in 1990. Early the following year, Senator Heinz was killed in a plane crash near Lower Merion. Teresa has three sons from her previous marriage to Heinz, Henry John Heinz IV, André Thierstein Heinz, and Christopher Drake Heinz. Heinz and Kerry were married on May 26, 1995, in Nantucket, Massachusetts.
Is there an answer to this question: When did Kerry and Teresa meet?

Answer: 1990


Problem: Biodiversity:

The history of biodiversity during the Phanerozoic (the last 540 million years), starts with rapid growth during the Cambrian explosion—a period during which nearly every phylum of multicellular organisms first appeared. Over the next 400 million years or so, invertebrate diversity showed little overall trend, and vertebrate diversity shows an overall exponential trend. This dramatic rise in diversity was marked by periodic, massive losses of diversity classified as mass extinction events. A significant loss occurred when rainforests collapsed in the carboniferous. The worst was the Permian-Triassic extinction event, 251 million years ago. Vertebrates took 30 million years to recover from this event.

In which event did the vertebrates collapse in the carboniferous?
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A:
unanswerable