Problem: Printed circuit board:

Other platings used are OSP (organic surface protectant), immersion silver (IAg), immersion tin, electroless nickel with immersion gold coating (ENIG), electroless nickel electroless palladium immersion gold (ENEPIG) and direct gold plating (over nickel). Edge connectors, placed along one edge of some boards, are often nickel plated then gold plated. Another coating consideration is rapid diffusion of coating metal into Tin solder. Tin forms intermetallics such as Cu5Sn6 and Ag3Cu that dissolve into the Tin liquidus or solidus(@50C), stripping surface coating or leaving voids.

Electroless silver electroless palladium immersion gold (ENEPIG) is an example of what?
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A: unanswerable


Problem: The red flag appeared as a political symbol during the French Revolution, after the fall of Bastille. A law adopted by the new government on October 20, 1789 authorized the Garde Nationale to raise the red flag in the event of a riot, to signal that the Garde would imminently intervene. During a demonstration on the Champs de Mars on July 17, 1791, the Garde Nationale fired on the crowd, killed up to fifty people. The government was denounced by the more radical revolutionaries. In the words of his famous hymn, the Marseillaise, Rouget de Lisle wrote: "Against us they have raised the bloody flag of tyranny!" (Contre nous de la tyrannie, l'entendard sanglant est leve). Beginning in 1790, the most radical revolutionaries adopted the red flag themselves, to symbolize the blood of those killed in the demonstrations, and to call for the repression of those they considered counter-revolutionary.
In what year did the most ardent revolutionaries in France adopt a red flag to symbolize the blood of their fallen comrades?
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Answer: 1790


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
On 26 July 2012, to coincide with the official start of the London 2012 Olympics and the issuing of a series of souvenir front covers, The Times added the suffix "of London" to its masthead.
What kind of front cover did The Times issue on 26 July 2012?
A: souvenir


Context and question: Although almost all ancient sources relating to crucifixion are literary, the 1968 archeological discovery just northeast of Jerusalem of the body of a crucified man dated to the 1st century provided good confirmatory evidence that crucifixions occurred during the Roman period roughly according to the manner in which the crucifixion of Jesus is described in the gospels. The crucified man was identified as Yehohanan ben Hagkol and probably died about 70 AD, around the time of the Jewish revolt against Rome. The analyses at the Hadassah Medical School estimated that he died in his late 20s. Another relevant archaeological find, which also dates to the 1st century AD, is an unidentified heel bone with a spike discovered in a Jerusalem gravesite, now held by the Israel Antiquities Authority and displayed in the Israel Museum.
What was the average age of Roman soldiers?
Answer: unanswerable


Question: The symbol $, usually written before the numerical amount, is used for the U.S. dollar (as well as for many other currencies). The sign was the result of a late 18th-century evolution of the scribal abbreviation "ps" for the peso, the common name for the Spanish dollars that were in wide circulation in the New World from the 16th to the 19th centuries. These Spanish pesos or dollars were minted in Spanish America, namely in Mexico City, Potosí, Bolivia; and Lima, Peru. The p and the s eventually came to be written over each other giving rise to $.
Is there an answer to this question: Which century signaled the end of the sign?

Answer: unanswerable


Problem: Detroit:

Detroit Medical Center formally became a part of Vanguard Health Systems on December 30, 2010, as a for profit corporation. Vanguard has agreed to invest nearly $1.5 B in the Detroit Medical Center complex which will include $417 M to retire debts, at least $350 M in capital expenditures and an additional $500 M for new capital investment. Vanguard has agreed to assume all debts and pension obligations. The metro area has many other hospitals including William Beaumont Hospital, St. Joseph's, and University of Michigan Medical Center.

How much will Vanguard spend to retire debt for DMC?
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A:
$417 M