Many scientists today are convinced that life exists elsewhere in the universe---life probably much like that on our own planet. They reason in the following way.
As far as astronomers can determine, the entire universe is built of the same matter. They have no reason to doubt that matter obeys the same laws in every part of the universe. Therefore, it is reasonable to guess that other stars, with their own planets, were born in the same way as our own solar system. What we know of life on earth suggests that life will arise wherever the proper conditions exist.
Life requires the right amount and kind of atmosphere. This eliminates all those planets in the universe that are not about the same size and weight as the earth. A smaller planet would lose its atmosphere; a larger one would hold too much of it.
Life also requires a steady supply of heat and light. This eliminates double stars, or stars that flare up suddenly. Only single stars that are steady sources of heat and light like our sun would qualify.
Finally, life could evolve only if the planet is just the right distance from its sun. With a weaker sun than our own, the planet would have to be closer to it. With a stronger sun, it would have to be farther away.
If we suppose that every star in the universe has a family of planets, then how many planets might support life? First, eliminate those stars that are not like our sun. Next eliminate most of their planets; they are either too far from or too close to their suns. Then eliminate all those planets which are not the same size and weight as the earth. Finally, remember that the proper conditions do not necessarily mean that life actually does exist on a planet. It may not have begun yet, or it may have already died out.
This process of elimination seems to leave very few planets on which earthlike life might be found. However, even if life could exist on only one planet in a million, there are so many billions of planets that this would still leave a vast number on which life could exist.
1. Astronomers believe that matter in different parts of the universe
A) has different laws.
B) has one common law.
C) shares the same laws
D) shares no common law.
2. The existence of life depends on all of the following factors EXCEPT
A) the right amount of atmosphere.B) our own solar system.
C) steady heat and light D) the right distance from the sun.
3. Which of the following statements is INCORRECT?
A) The planet must be as big and heavy as the earth.
B) Proper conditions are essential to the existence of life
C) Double stars can provide steady light and heat.
D) The distance between a planet and its sun should be right.
4. What kind of planet might NOT support life?
A) Most of the planets of the stars.
B) Stars similar to our sun.
C) Planets similar to the earth.
D) Planets with proper conditions.
5. At the end of the passage the author suggests that
A) it is impossible for life to exist on planets.
B) earthlike life could only exist on a few planets.
C) life could exist on only one planet in a million.
D) life could exist on a great number of planets.
KEY:CBCAD
英语听力视频:梦露未见过物品公之于众
英美大不同相声版(视频)
TED演讲视频: 朱莉娅斯威尼和女儿的“谈话”
Olympic torch scales Snowdon in Wales
TED演讲:畅想电子游戏
英语听力:殿堂级吃货必看-舌尖上的中国
这就是新东方英语篮球营的魅力
学习伦敦奥运会的礼节
英语听力视频:美国小朋友怎么看哈利·波特
英语听力:美国熊孩子如何看热门视频—复仇者联盟
英语听力:170余幅农民工画像走进绘画艺术展
林书豪搞怪视频:教你如何上哈佛(中英)
英语听力:《大独裁者》卓别林最后的演讲(视频)
老外吊丝12类人超强模仿:各国各地域惟妙惟肖(视频)
4分钟了解俄罗斯:Russia you never konw(视频)
英语听力视频:扎克伯格谈Facebook盈利秘诀
英语听力视频:法国准备第65届戛纳国际电影节
英语听力视频:比尔•盖茨向中国人民拜年(双语)
英语听力视频:新发现揭开2012年世界末日的神话
英语听力视频:"最美女教师"张丽莉术后恢复
英语听力视频:希腊传奇人物Manolis Glezos
听力练习:考古学家在安阳古墓中发现完好无损壁画
美国孩子如何看热门视频:Facebook与父母
李开复俞敏洪电视英语携手亮相 幽默教学
英语听力:美国19岁男生为同性恋婚姻的辩护(视频)
英语听力视频:波音公司创建787梦想飞机
教师的烦恼(视频)
英语听力视频:摇滚巨星将参加伦敦奥运会
视频:美国副总统拜登、国务卿克林顿设宴迎习近平访美
英语听力:世界卫生组织号召全球履行禁烟
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |