Article: The hole walls for boards with two or more layers can be made conductive and then electroplated with copper to form plated-through holes. These holes electrically connect the conducting layers of the PCB. For multi-layer boards, those with three layers or more, drilling typically produces a smear of the high temperature decomposition products of bonding agent in the laminate system. Before the holes can be plated through, this smear must be removed by a chemical de-smear process, or by plasma-etch. The de-smear process ensures that a good connection is made to the copper layers when the hole is plated through. On high reliability boards a process called etch-back is performed chemically with a potassium permanganate based etchant or plasma. The etch-back removes resin and the glass fibers so that the copper layers extend into the hole and as the hole is plated become integral with the deposited copper.

Question: What's the minimum number of layers a PCB can have to be considered "multi-layer"?
Ans: three

Article: The situation became so tense that war with the United States seemed imminent. On April 22, 1914, on the initiative of Felix A. Sommerfeld and Sherburne Hopkins, Pancho Villa traveled to Juarez to calm fears along the border and asked President Wilson's emissary George Carothers to tell "Senor Wilson" that he had no problems with the American occupation of Veracruz. Carothers wrote to Secretary William Jennings Bryan: "As far as he was concerned we could keep Vera Cruz [sic] and hold it so tight that not even water could get in to Huerta and . . . he could not feel any resentment". Whether trying to please the U.S. government or through the diplomatic efforts of Sommerfeld and Carothers, or maybe as a result of both, Villa stepped out from under Carranza's stated foreign policy.

Question: To which Secretary did Carothers write?
Ans: Secretary William Jennings Bryan

Article: In mid-November The Shevchenko Ukrainian Language Society was officially registered. On November 19, 1989, a public gathering in Kiev attracted thousands of mourners, friends and family to the reburial in Ukraine of three inmates of the infamous Gulag Camp No. 36 in Perm in the Ural Mountains: human-rights activists Vasyl Stus, Oleksiy Tykhy, and Yuriy Lytvyn. Their remains were reinterred in Baikove Cemetery. On November 26, 1989, a day of prayer and fasting was proclaimed by Cardinal Myroslav Lubachivsky, thousands of faithful in western Ukraine participated in religious services on the eve of a meeting between Pope John Paul II and Soviet President Gorbachev. On November 28, 1989, the Ukrainian SSR's Council for Religious Affairs issued a decree allowing Ukrainian Catholic congregations to register as legal organizations. The decree was proclaimed on December 1, coinciding with a meeting at the Vatican between the pope and the Soviet president.

Question: When was The Shevchenko Ukrainian Language Society made official?
Ans: mid-November

Article: The Famicom contained no lockout hardware and, as a result, unlicensed cartridges (both legitimate and bootleg) were extremely common throughout Japan and the Far East. The original NES (but not the top-loading NES-101) contained the 10NES lockout chip, which significantly increased the challenges faced by unlicensed developers. Tinkerers at home in later years discovered that disassembling the NES and cutting the fourth pin of the lockout chip would change the chip's mode of operation from "lock" to "key", removing all effects and greatly improving the console's ability to play legal games, as well as bootlegs and converted imports. NES consoles sold in different regions had different lockout chips, so games marketed in one region would not work on consoles from another region. Known regions are: USA/Canada (3193 lockout chip), most of Europe (3195), Asia (3196) and UK, Italy and Australia (3197). Since two types of lockout chip were used in Europe, European NES game boxes often had an "A" or "B" letter on the front, indicating whether the game is compatible with UK/Italian/Australian consoles (A), or the rest of Europe (B). Rest-of-Europe games typically had text on the box stating "This game is not compatible with the Mattel or NES versions of the Nintendo Entertainment System". Similarly, UK/Italy/Australia games stated "This game is only compatible with the Mattel or NES versions of the Nintendo Entertainment System".

Question: What was the lockout chip number for most of Europe, save the UK and Italy?
Ans:
3195