新概念英语第三册听力音频MP3在线练习lesson55

2021-12-27 10:29:42来源：网络

【资料库】第一册语法逐句精讲新概念英语2第三册经典句子解析新概念英语30天寒假学习计划
【课后题及答案解析】新概念英语第一册新概念英语第二册新概念英语第三册新概念英语第四册
【经验分享】学习新概念英语如何提升英语水平? 自学四大经典学习方法新概念学习方法及经验

　　新概念三册的备考练习中，对于美音版的音频内容，大家也要进行重点练习。毕竟这部分内容，对于大家来说，也是比较重要的备考。加强新概念三音频资料的有效练习，可以帮助大家更好的提高新概念英语能力，巩固英语基础。

新概念英语第三册美音点击试听

　　Lesson 55

　　From the earth: Greetings

　　来自地球的问候

　　Listen to the tape then answer the question below.

　　听录音，然后回答以下问题。

　　Which life forms are most likely to develop on a distant planet?

　　Recent developments in astronomy have made it possible to detect planets in our won Milky Way and in other galaxies. This is a major achievement because, in relative terms, planets are very small and old not emit light. Finding planets is proving hard enough, but finding life on them will prove infinitely more difficult. The first question to answer is whether a planet can actually support life. In our won solar system, for example, Venus is far too hot and Mars is far too cold to support life. Only the Earth provides ideal conditions, and even here it has taken more than four billion years for plant and animal life to evolve.

　　Whether a planet can support life depends on the size and brightness of its star, that is its 'sun'. Imagine a star up t twenty times larger, brighter, brighter and hotter than our own sun. A planet would have to be a very long way from it to be capable of supporting life. Alternatively, if the star were small, the life-supporting planet would have to have a close orbit round it and also provide the perfect conditions for life forms to develop. But how would we find such a planet? At present, there is no telescope in existence that is capable of detecting the presence of life. The development of such a telescope will be one of the great astronomical projects of the twenty-first century.

　　It is impossible to look for life on another planet using earth-based telescopes. Our own warm atmosphere and the heat generated by the telescope would make it impossible to detect objects as small as planets. Even a telescope in orbit round the earth, like the very successful Hubble telescope, would not be suitable because of the dust particles iron solar system. A telescope would have to be as far away as the planet Jupiter to look for life in outer space, because the dust becomes thinner the further we travel towards the outer edges of our own solar system. Once we detected a planet, we would have to find a way of blotting out the light from its star, so that we would be able to 'see' the planet properly and analyze its atmosphere. In the first instance, we would be looking for plant life, rather than 'little green men'. The life forms most likely to develop on a planet would be bacteria. It is bacteria that have generated the oxygen we breathe on earth. For most of the earth's history they have been the only form of life on our planet. As Earth-dwellers, we always cherish the hope that we will be visited by little green men and that we will be able to communicate with them. But this hope is always in the realms of science fiction. If we were able to discover lowly forms of life like bacteria on another planet, it would completely change our view of ourselves. As Daniel Goldin of NASA observed, 'Finding life elsewhere would change everything. No human endeavor or thought would be unchanged by it."

　　New words and expressions 生词和短语

　　astronomy

　　n. 天文学

　　relative

　　adj. 相对的

　　infinitely

　　adv. 无限地，无穷地

　　solar

　　adj. 太阳系的

　　Venus

　　n. 金星

　　Mars