评论
打印
Since early times, people have been fascinated with the idea of life existing somewhere else besides earth.
很早的时候人们就开始对地球之外的生命充满着遐想。
Until recently, scientists believed that life on other planets was just a hopeful dream.
直到最近，科学家还相信外星生命只是一个美好的愿景。
But now they are beginning to locate places where life could form.
但是现在，他们已经开始在地球之外发现可能孕育生命的地方了。
In 1997, they saw evidence of planets near other stars like the sun.
1997年，他们找到证据证明与太阳类似恒星附近有行星的存在。
But scientists now think that life could be even nearer in our own solar system.
他们现在甚至认为我们的太阳系就可能有外星生命。
One place scientists are studying very closely is Europa, a moon of Jupiter.
他们正在密切观察的对象之一是欧罗巴，木星的卫星。
Space probes have provided evidence that Europa has a large ocean under its surface.
航天探测器探测数据证明木卫二表层之下蕴藏着一片汪洋大海。
The probes have also made scientists think that under its surface Europa has a rocky core giving off volcanic heat.
科学家们还相信木卫二的岩心是不断散发着热量的火山热源。
Water and heat from volcanic activity are two basic conditions needed for life to form.
水和火山活动散发的热量是生命存在的两个基本前提。
A third is certain basic chemicals such as carbon, oxygen and nitrogen.
第三个必要条件是化学成分，如：碳、氧、氮。
Scientists believe there might be such chemicals lying at the bottom of Europa's ocean.
科学家认为木卫二地表下的海床上一定存在这些化学物质。
They may have already created life, or may be about to.
它们可能已经孕育了生命。
You may wonder if light is also needed for life to form.
你可能会想阳光是不是生命形成的必要条件。
Until recently, scientists thought that light was essential.
科学家最近对此得出肯定的结论。
But now, places have been found on earth that are in total blackness, such as caves several miles beneath the surface, and bacteria, primitive forms of life, have been seen there.
但是现在人们在地球上一些完全暗无天日的地方也发现了细菌等原始的生命形式，比如地面几英里以下的洞穴中。
So the lack of light in Europa's subsurface ocean doesn't automatically rule out life forming.
因此，并不能仅仅因为木卫二地下海洋缺乏阳光就排除其孕育生命的可能。
Questions 16 to 18 are based on the passage you have just heard.
请根据刚刚听到的内容回答16-18题。
Question 16. What did scientists once believe according to the passage?
问题16：科学家过去的想法是怎样的？
Question 17. What have scientists found about Europa, a moon of Jupiter?
问题17：关于木星的卫星木卫二科学家们有什么发现？
Question 18. What scientists come to know recently about the formation of life?
问题18：科学家最近对生命的形成有什么新的认识？
译文属可可原创，仅供学习和交流使用，未经允许不得转载
