Subscribe to Posts
Subscribe to Comments
字号: | |

2009年6月英语四级阅读备考(12)

发帖者 吴怀唐 On 下午8:17
  The discovery of planets around distant stars has become like space-shuttle launches-newsworthy but just barely. With some 50 extrasolar planets under their belt, astronomers have to announce something really strange to get anyone's attention.

  Last week they did just that. Standing in front of colleagues and reporters at the American Astronomical Society's semiannual meeting in San Diego, the world's premier planet-hunting team-astronomer Geoffrey Marcy of the University of California, Berkeley, and his colleagues-presented not one but two remarkable finds. The first is a pair of planets, each about the mass of Jupiter, that whirl around their home star 15light years from Earth in perfect lockstep. One takes 30 days to complete an orbit, the other exactly twice as long. Nobody has ever seen such a configuration. But the second discovery is far stranger-a solar system 123 light-years away in the constellation Serpens, that harbors one "ordinary" planet and another so huge-17 times as massive as Jupiter-that nobody can quite figure out what it can be. It is, says Marcy, "a bit frightening".

  What's frightening is that these discoveries make it clear how little astronomers know about planets, and they add to the dawning realization that our solar system-and by implication Planet Earth-may be a cosmic oddball. For years theorists figured that other stars would have planets more or less like the ones going around the sun. But starting with the 1995 discovery of the first extrasolar planet-a gassy monster like Jupiter but orbiting seven times as close to its star as Mercury orbits around our sun-each new find has seemed stranger than the last. Searchers have found more "hot Jupiters" like that first discovery. These include huge planets that career around their stars not in circular orbits but in elongated ones; their gravity would send any Earthlike neighbors flying off into space. Says Princeton astronomer Scott Tremaine: "Not a single prediction for what we'd find in other systems has turned out to correct."

  Last week's giant was the most unexpected discovery yet. Conventional theory suggests that it must have formed like a star, from a collapsing cloud of interstellar gas. Its smaller companion, only seven times Jupiter's mass, is almost certainly a planet, formed by the buildup of gas and dust left over from a star's formation. Yet the fact that these two orbs are so close together suggests to some theorists that they must have formed together-so maybe the bigger one is a planet after all.

  Or maybe astronomers will have to rethink their definition of "planet". Just because we put heavenly objects into categories doesn't mean the distinctions are necessarily valid. And as Tremaine puts it, "When your classification schemes start breaking down, you know you're learning something exciting. This is wonderful stuff."

  1. The author believes that .

  [A] the discovery of planets is as important as the launch of space shuttles

  [B] astronomers have been making a lot of discoveries of planets

  [C] the public have no interest in astronomical discoveries

  [D] there is little for astronomers to discover now

  2. The two finds are remarkable in that .

  [A] the planets are far from our solar system

  [B] the sizes of the planets are too huge

  [C] astronomers have never seen similar orbiting pattern and size before

  [D] scientists can not figure out what they can be

  3. By saying that our solar system "may be a cosmic oddball", the author intends to render the idea that .

  [A] other stars have planets more or less like the one going around the sun

  [B] the orbits of extrasolar planets around their stars are elongated ones

  [C] the way planets orbiting around the sun in our solar system is quite unique

  [D] planets in other systems are generally huger than the ones in ours

  4. The case of the giant heavenly body demonstrates that .

  [A] conventional theory can not explain such astronomical phenomenon satisfactorily

  [B] it is either a star or a planet

  [C] it was formed like a star and orbits like a planet

  [D] theorists give a wrong definition of "planet"

  5. The best title for this passage could be .

  [A] New Planetary Puzzlers

  [B] Two Remarkable Finds

  [C] A Redefinition of "Planet"

  [D] "Hot Jupiters" Challenging Conventional Theory

  答案:B C C A A

  词汇注释

  semiannual adj. 半年一次的

  premier adj. 第一的,首要的

  Jupiter n. 木星

  lockstep n. 前后紧接,步伐一致

  configuration n. [天](行星等的)相对位置,方位

  constellation n. [天]星群,星座

  Serpens n. [天]巨蛇座

  oddball n. 古怪的人,古怪的事物

  Mercury n. [天]水星

  elongate v. 拉长,(使)伸长,延长

  interstellar adj. 星际的

  orb n. 球,天体,圆形物

  题目分析

  1. 答案为B,属事实细节题。文章中提到"with some 50 extrasolar planets under their belt"来说明为什么天文发现已经很多,难以吸引众人,所以应该选B。

  2.答案为C,属事实细节题。文中第二段指出第一个发现里的两颗行星的运行轨道排列方式前所未见,第二个发现里面有一颗是木星体积17倍的巨大星体。其它各项在原因方面都罗列的过于简单,只有C把这两点都包括了,所以是正确答案。

  3.答案为C,属推理判断题。文中第三段举了几个例子说明1995年以后天文发现的太阳系外行星围绕母星运行的方式跟太阳系行星的运行方式大不相同,由此解释我们的太阳系是一个宇宙中的异数。

  4.答案为A,属推理判断题。文中介绍了传统理论解释该天文发现时所面临的困境。它看似像恒星,但运行轨道又接近行星,因此难以确定它究竟是什么。显然,传统理论无法令人满意地解释这种天体。

  5.答案为A,属推理判断题。文章重点写这次天文发现的奇异之处,以及它们带给天文学家的困惑。文章最后一段说maybe astronomers will have to rethink their definition of "planet"。所以答案A最为合适。

  对围绕着遥远的恒星运行的行星的发现就好像发射航天飞机一样--有新闻价值但仅此而已。现在天文学家已经在太阳系之外发现了50多颗行星,他们只有发现一些真正奇怪的东西才能吸引人们的注意力。

  上周的发现就属于此类。在圣迭戈举行的美国天文学会半年一度的会议上,来自加州大学伯克利分校的世界顶级行星搜寻小组天文学家杰弗里.马西和他的同事们向同行和新闻记者展示了两项惊人的发现。第一项是一对行星,每个大小和木星相仿,它们一前一后绕着距离地球15光年的一颗行星运行。其中一颗三十天沿轨道运行一周,而另一颗所需时间恰好是它的运行周期的两倍。这种相对位置以前从未有人见过。但第二项发现更令人称奇--在巨蛇座内距离地球123光年的地方有一个太阳系,它拥有一颗"普通"行星和一颗体积足有木星的17倍那么大的行星--这么巨大的体积叫人不知道它会是什么。马西说它"有点惊人"。

  真正令人震惊的是,这些发现说明天文学家对于行星的了解十分有限,并且让人们开始认识到我们的太阳--不言而喻,还有地球这颗行星--也许是宇宙中的异数。很多年来理论学家们都一致认为其它恒星的行星和围绕太阳运行的行星多少有些相似。但1995年发现了第一颗太阳系之外的行星--一颗像木星一样的巨大气态星球,它围绕自己的母星运行的距离比水星绕着太阳运行时的距离还近7倍。从这一发现开始,每一个新发现似乎都比上一次发现更令人惊奇。搜寻者们已经发现了更多第一次发现中的那种"热木星"。这些发现中有一些巨大的行星,它们围绕母星运行的轨道不是圆形的,而是延长的;它们的重力会使周围像地球这样的星体逃逸到太空中去。普林斯顿的天文学家斯科特.特里梅因说:"我们对于会在其它星系里的发现所作的预测没有一次是准确的。"

  上周发现的这颗巨星是目前为止最出人意料的发现。传统的理论认为它一定像一颗恒星那样是有一团星际气体形成的压缩星云组成的。它那体积较小的伴侣只有木星体积的7倍,几乎可以确定是一颗行星,是由恒星形成时留下的气体和灰尘累积形成的。不过这两个天体如此接近,一些理论家认为它们一定是一起形成的--那样的话,较大的那一颗也是一颗行星。

  也许天文学家们必须重新思考他们对于"行星"的定义。我们把天体进行分类并不意味着我们的这种区分必然有效。正如特里梅因所说:"当你的分类模式开始不起作用的时候,你就知道你正在了解某些令人激动的事情。这是很有趣的。"

相关阅读:2009年6月英语四级阅读备考汇总
反应: 

0 Response to '2009年6月英语四级阅读备考(12)'

发表评论