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The Germans expected to negotiate an end to the war but immediately ordered an advance on Paris; by 15 September Moltke issued the orders for an investment of Paris and on 20 September the encirclement was complete. Bismarck met Favre on 18 September at the Château de Ferrières and demanded a frontier immune to a French war of revenge, which included Strasbourg, Alsace and most the Moselle department in Lorraine of which Metz was the capital. In return for an armistice for the French to elect a National Assembly, Bismarck demanded the surrender of Strasbourg and the fortress city of Toul. To allow supplies into Paris, one of the perimeter forts had to be handed over. Favre was unaware that the real aim of Bismarck in making such extortionate demands was to establish a durable peace on the new western frontier of Germany, preferably by a peace with a friendly government, on terms acceptable to French public opinion. An impregnable military frontier was an inferior alternative to him, favoured only by the militant nationalists on the German side.

Bismarck demanded the surrender of Strasbourg and what fortress city?
Answer: Toul
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One of the few city states who managed to maintain full independence from the control of any Hellenistic kingdom was Rhodes. With a skilled navy to protect its trade fleets from pirates and an ideal strategic position covering the routes from the east into the Aegean, Rhodes prospered during the Hellenistic period. It became a center of culture and commerce, its coins were widely circulated and its philosophical schools became one of the best in the mediterranean. After holding out for one year under siege by Demetrius Poliorcetes (304-305 BCE), the Rhodians built the Colossus of Rhodes to commemorate their victory. They retained their independence by the maintenance of a powerful navy, by maintaining a carefully neutral posture and acting to preserve the balance of power between the major Hellenistic kingdoms.

What military force helped Rhodes maintain their independence?
Answer: navy
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There is a theory that vinyl records can audibly represent higher frequencies than compact discs. According to Red Book specifications, the compact disc has a frequency response of 20 Hz up to 22,050 Hz, and most CD players measure flat within a fraction of a decibel from at least 20 Hz to 20 kHz at full output. Turntable rumble obscures the low-end limit of vinyl but the upper end can be, with some cartridges, reasonably flat within a few decibels to 30 kHz, with gentle roll-off. Carrier signals of Quad LPs popular in the 1970s were at 30 kHz to be out of the range of human hearing. The average human auditory system is sensitive to frequencies from 20 Hz to a maximum of around 20,000 Hz. The upper and lower frequency limits of human hearing vary per person.

What is generally the lowest sound a human can hear?
Answer:
20 Hz