The problem: Answer a question about this article:
Y-Gerat was the most complex system of the three. It was, in effect, an automatic beam-tracking system, operated through the bomber's autopilot. The single approach beam along which the bomber tracked was monitored by a ground controller. The signals from the station were retransmitted by the bomber's equipment. This way the distance the bomber travelled along the beam could be precisely verified. Direction-finding checks also enabled the controller to keep the crew on an exact course. The crew would be ordered to drop their bombs either by issue of a code word by the ground controller, or at the conclusion of the signal transmissions which would stop. Although its maximum usable range was similar to the previous systems, it was not unknown for specific buildings to be hit.
Which system was the most complex of the three?
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The answer: Y-Gerat

The problem: Answer a question about this article:
This season saw the first Idol Gives Back telethon-inspired event, which raised more than $76 million in corporate and viewer donations. No contestant was eliminated that week, but two (Phil Stacey and Chris Richardson) were eliminated the next. Melinda Doolittle was eliminated in the final three.
Who was eliminated on the Top 3 show?
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The answer: Melinda Doolittle

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During the 12th century, the institutions of central government, which had hitherto accompanied the royal English court as it moved around the country, grew in size and sophistication and became increasingly fixed in one place. In most cases this was Westminster, although the royal treasury, having been moved from Winchester, came to rest in the Tower. While the City of Westminster developed into a true capital in governmental terms, its distinct neighbour, the City of London, remained England's largest city and principal commercial centre, and it flourished under its own unique administration, the Corporation of London. In 1100, its population was around 18,000; by 1300 it had grown to nearly 100,000.
What was the administration which governed the City of London called?
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The answer: the Corporation of London

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The differential analyser, a mechanical analog computer designed to solve differential equations by integration, used wheel-and-disc mechanisms to perform the integration. In 1876 Lord Kelvin had already discussed the possible construction of such calculators, but he had been stymied by the limited output torque of the ball-and-disk integrators. In a differential analyzer, the output of one integrator drove the input of the next integrator, or a graphing output. The torque amplifier was the advance that allowed these machines to work. Starting in the 1920s, Vannevar Bush and others developed mechanical differential analyzers.
What type of mechanisms did the differential analyzer use?
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The answer:
wheel-and-disc