Life in the Universe 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. 答案:CBCAD
2016届高考英语临考冲刺高分之路:完形填空
2016届高考英语临考冲刺高分之路:主谓一致
2016届高考英语临考冲刺高分之路:引导名词性从句的连接词
2016英语必考点逐个击破快速提分:考点妙解6 冠词
2016届高考英语临考冲刺高分之路:部分倒装用法归纳
2016届高考英语临考冲刺高分之路: 情景交际
2016英语必考点逐个击破快速提分:考点妙解2 非谓语动词
2016英语必考点逐个击破快速提分:考点妙解7 动词
2016届高考英语临考冲刺高分之路:先行词和关系词二合一
2016届高考英语临考冲刺高分之路:虚拟语气练习题
2016届高考英语临考冲刺高分之路:虚拟语气理论详解(一)
2016届高考英语临考冲刺高分之路:特殊的虚拟语气词:should
2016届高考英语临考冲刺高分之路:提纲类
2016英语必考点逐个击破快速提分:考点妙解8 名词
2016届高考英语临考冲刺高分之路:主旨大意
2016届高考英语临考冲刺高分之路:形容词比较级和最高级表示否定意义
2016届高考英语临考冲刺高分之路:形容词和副词
2016届高考英语临考冲刺高分之路: 非谓语动词
2016届高考英语临考冲刺高分之路:疑问词+ever的用法
2016英语必考点逐个击破快速提分:考点妙解4 介词
2016英语必考点逐个击破快速提分:考点妙解5 代词
2016届高考英语临考冲刺高分之路:动词
2016届高考英语临考冲刺高分之路:推理判断
2016英语必考点逐个击破快速提分:考点妙解16 短文改错
2016届高考英语临考冲刺高分之路:现在进行时的特殊用法
2016届高考英语临考冲刺高分之路: 冠词
2016届高考英语临考冲刺高分之路:虚拟语气理论详解(二)
Finding a way
2016英语必考点逐个击破快速提分:考点妙解17 情景交际
2016英语必考点逐个击破快速提分:考点妙解18 名词
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