Problem: Hydrogen:

In more recent applications, hydrogen is used pure or mixed with nitrogen (sometimes called forming gas) as a tracer gas for minute leak detection. Applications can be found in the automotive, chemical, power generation, aerospace, and telecommunications industries. Hydrogen is an authorized food additive (E 949) that allows food package leak testing among other anti-oxidizing properties.

How is hydrogen used as a food additive?
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A: allows food package leak testing


Problem: At the end of the last ice age, what are now the British Isles were joined to the European mainland as a mass of land extending north west from the modern-day northern coastline of France, Belgium and the Netherlands. Ice covered almost all of what is now Scotland, most of Ireland and Wales, and the hills of northern England. From 14,000 to 10,000 years ago, as the ice melted, sea levels rose separating Ireland from Great Britain and also creating the Isle of Man. About two to four millennia later, Great Britain became separated from the mainland. Britain probably became repopulated with people before the ice age ended and certainly before it became separated from the mainland. It is likely that Ireland became settled by sea after it had already become an island.
When sea levels rose what occured in the British Isles area?
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Answer: separating Ireland from Great Britain


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
On January 13, 1991, Soviet troops, along with the KGB Spetsnaz Alpha Group, stormed the Vilnius TV Tower in Lithuania to suppress the independence movement. Fourteen unarmed civilians were killed and hundreds more injured. On the night of July 31, 1991, Russian OMON from Riga, the Soviet military headquarters in the Baltics, assaulted the Lithuanian border post in Medininkai and killed seven Lithuanian servicemen. This event further weakened the Soviet Union's position internationally and domestically, and stiffened Lithuanian resistance.
How many civilians died in the attack?
A: Fourteen


Context and question: The Order of Preachers (Latin: Ordo Praedicatorum, hence the abbreviation OP used by members), more commonly known after the 15th century as the Dominican Order or Dominicans, is a Roman Catholic religious order founded by the Spanish priest Saint Dominic de Guzman in France and approved by Pope Honorius III (1216–27) on 22 December 1216. Membership in this "mendicant" order includes friars, nuns, active sisters, and lay or secular Dominicans (formerly known as tertiaries, though recently there has been a growing number of Associates, who are unrelated to the tertiaries) affiliated with the order.
After the 15th century, what was the Order of Preachers known as?
Answer: the Dominican Order


Question: In January 1790, Burke read Dr. Richard Price's sermon of 4 November 1789 entitled, A Discourse on the Love of our Country, to the Revolution Society. That society had been founded to commemorate the Glorious Revolution of 1688. In this sermon Price espoused the philosophy of universal "Rights of Men". Price argued that love of our country "does not imply any conviction of the superior value of it to other countries, or any particular preference of its laws and constitution of government". Instead, Price asserted that Englishmen should see themselves "more as citizens of the world than as members of any particular community".
Is there an answer to this question: What was the Revolution Society commemorating?

Answer: the Glorious Revolution of 1688


Question: In 1932, Hayek suggested that private investment in the public markets was a better road to wealth and economic co-ordination in Britain than government spending programs, as argued in a letter he co-signed with Lionel Robbins and others in an exchange of letters with John Maynard Keynes in The Times. The nearly decade long deflationary depression in Britain dating from Churchill's decision in 1925 to return Britain to the gold standard at the old pre-war, pre-inflationary par was the public policy backdrop for Hayek's single public engagement with Keynes over British monetary and fiscal policy, otherwise Hayek and Keynes agreed on many theoretical matters, and their economic disagreements were fundamentally theoretical, having to do almost exclusively with the relation of the economics of extending the length of production to the economics of labour inputs.
Is there an answer to this question: What other notable figure signed the letter in which Hayek made his statement regarding private investment?

Answer:
Lionel Robbins