Question: 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.
Is there an answer to this question: What connects the conducting layers of the PAB?

Answer: unanswerable


Question: The Nazi regime under Adolf Hitler came to power in 1933, and along with Mussolini's Italy sought to gain control of the continent by the Second World War. Following the Allied victory in the Second World War, Europe was divided by the Iron Curtain. The countries in Southeastern Europe were dominated by the Soviet Union and became communist states. The major non-communist Southern European countries joined a US-led military alliance (NATO) and formed the European Economic Community amongst themselves. The countries in the Soviet sphere of influence joined the military alliance known as the Warsaw Pact and the economic bloc called Comecon. Yugoslavia was neutal.
Is there an answer to this question: Who led the Nazis?

Answer: Adolf Hitler


Question: The Gospel of Matthew describes many women at the crucifixion, some of whom are named in the Gospels. Apart from these women, the three Synoptic Gospels speak of the presence of others: "the chief priests, with the scribes and elders"; two robbers crucified, one on Jesus' right and one on his left, whom the Gospel of Luke presents as the penitent thief and the impenitent thief; "the soldiers", "the centurion and those who were with him, keeping watch over Jesus"; passers-by; "bystanders", "the crowds that had assembled for this spectacle"; and "his acquaintances"
Is there an answer to this question: Who kept watch over Jesus?

Answer: the soldiers


Question: Liverpool produced a number of nationally and internationally successful popular singers in the 1950s, including traditional pop stars Frankie Vaughan and Lita Roza, and one of the most successful British rock and roll stars in Billy Fury. Many Lancashire towns had vibrant skiffle scenes in the late 1950s, out of which by the early 1960s a flourishing culture of beat groups began to emerge, particularly around Liverpool and Manchester. It has been estimated that there were around 350 bands active in and around Liverpool in this era, often playing ballrooms, concert halls and clubs, among them the Beatles. After their national success from 1962, a number of Liverpool performers were able to follow them into the charts, including Gerry & the Pacemakers, the Searchers and Cilla Black. The first act to break through in the UK who were not from Liverpool, or managed by Brian Epstein, were Freddie and the Dreamers, who were based in Manchester, as were Herman's Hermits and the Hollies. Led by the Beatles, beat groups from the region spearheaded the British Invasion of the US, which made a major contribution to the development of rock music. After the decline of beat groups in the late 1960s the centre of rock culture shifted to London and there were relatively few local bands who achieved national prominence until the growth of a disco funk scene and the punk rock revolution in the mid and late 1970s.
Is there an answer to this question: How many bands were active in the Liverpool area in the 1960s?

Answer:
350