（精）全新版大学英语综合教程第三册课件 Unit 4.ppt

Unit Four Extraterrestrials Space Exploration Space Exploration In 1981 the USA launched a space shuttle, the first reusable space craft. Space Exploration On Oct. 15, 2003, Shenzhou V sent Chinas first astronaut Yang Liwei into space, making China the third nation following the former Soviet Union and the United States to place a human in orbit. China hopes to launch the Shenzhou VI next year in a flight that will place two astronauts in orbit for between five and seven days. Shenzhou V The author Isaac Asimov (1920-1992): Russian-born American author and biochemist, widely known for his first-rate works of science fiction for the layperson. He published about 500 volumes. The author Asimov is especially adept at popularizing scientific writing. His important works include I, Robot (1950), the Foundation trilogy (1951-53), The Robots of Dawn (1983), and Opus 300 (1984) Cultural Notes Venus: the second major planet in order of distance from the Sun. Also known as Hesperus, the evening star, or Phosphorus, the morning star, Venus can be the brightest object in the sky after the Sun and Moon and follows a near-circular path some 106 million kilometers from the Sun, taking 225 days to complete one orbit. Cultural Notes Extraterrestrial life: life-forms that may have evolved on other planets. There is no hard evidence at present that life exists other than on the Earth. Most UFOs have been satisfactorily explained as being natural or man-made, and the Viking missions to Mars were inconclusive in testing for the existence of life on that planet. Cultural Notes Nevertheless, searches have been and are being made for signs that life has arisen in other parts of the universe. Certain knowledge either that life is confined to planet Earth or has been found elsewhere would have the profoundest philosophical implications for mankind. Cultural Notes Factors con