[填空题]A Perpetual Motion Machine is a fascinating and long-discussed topic that moves well beyond the scope of physics. In short, a perpetual motion machine can be likened to a magic cow that continues to live and breathe and yet needs no sustenance. A perpetual motion engine installed in a ear would continue to run indefinitely but would need neither gas tank nor petrol. Of course, as a perpetual motion machine is in violation of natural laws, it will likely never move out of the realm of imagination and into reality. When the phrase "perpetual motion machine" is entered into Google’s search engine, 34,400 items are returned. Of these 34,400 items, the forty-first to the forty-fifth hold reasonable interest and will be further discussed herein.
41. Myths and legends
Long before the advent of the steam engine, human beings have ruminated on the possibility of a perpetual motion machine. Throughout history, many have attempted to invent such a device, though none ha

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