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《新概念第四册 - 35 Lrc歌词》
╔------------------------------SUPERLYRICS---╗ |九九Lrc歌词网免费提供Lrc歌词搜索、Lrc歌词下载| | 感谢你推荐www.99Lrc.net给你的好友使用 | ╚---------------------------------------.NET-╝ 歌手名:新概念第四册 歌曲名:35 专辑名:hgjjhjj 感谢{hjgkjg}辛苦编辑Lrc歌词,并提供给大家分享 Lesson 35 Space odyssey First listen and then answer the following question. When will it be possible for us to think serio-usly about colonizing Mars? The Moon is likely to become the industrial hub of the SOLAR system, supplying the rocket fuels for its ships, easily obtaina-ble from the lunar rocks in the form of liquid oxygen. The reason lies in its gravity. Because the Moon has only an eightieth of the Earth's mass, it requires 97 per cent less energy to travel the quarter of a million miles from the Moon to Earth-orbit than the 200mile-journey from Earth's surface into orbit!This may sound fantastic, but it is easily calculated. To escape from the Earth in a rocket, one must travel at seven miles per second. The comparable speed from the Moon is only 1.5 miles per second. Because the gravity on the Moon's surface is only a sixth of Earth's (remember how easily the Apo-llo astronauts bounded along), it takes much less energy to accelerate to that 1.5 miles per second than it does on Earth. Moon-dwellers will be able to fly in space at only three per cent of the cost of similar journeys by their terres-trial cousins. Arthur C.Clark once suggested a revolutionary idea passes through three phases: 1 'It's imposs-ible- don't waste my time.' 2 'It's possib-le, but not worth doing. '3 'I said it was a good idea all along.' The idea of colonizing Mars- a world 160times more distant than the Moon- will move decisively from the second pha-se to the third, when a signif-icant number of people are living perm-anently in space. Mars has an extraordinary fascination for would-be voyagers. AMERICA, Russia and Europe are filled with enthusiasts-many of them serious and senior scientists-who dream of sending people to it. Their aim is understandable. It is the one world in the Solar System that is most like the Earth. It is a world of red sandy deserts (hence its name-the Red Planet), cloudless skies, savage sandsto-rms, chasms wider than the Grand Canyon and at least one mountain more than twice as tall as Everest. It seems ideal for settlement.
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