请教OG10 137、140

Passage 23

New observations about the age of some globular clusters in our Milky Way galaxy have cast doubt on a long-held theory about how the galaxy was formed. The Milky Way contains about 125 globular clusters (compact groups of anywhere from several tens of thousands to perhaps a million stars) distributed in a roughly spherical halo around the galactic nucleus. The stars in these clusters are believed to have been born during the formation of the galaxy, and so may be considered relics of the original galactic nebula, holding vital clues to the way of the formation took place.

The conventional theory of the formation of the galaxy contends that roughly 12 to 13 billion years ago the Milky Way formed over a relatively short time (about 200 million years) when a spherical cloud of gas collapsed under the pressure of its own gravity into a disc surrounded by a halo. Such a rapid formation of the galaxy would mean that all stars in the halo should be very nearly the same age.

However, the astronomer Michael Bolte has found considerable variation in the ages of globular clusters. One of the clusters studied by Bolte is 2 billions years older than most other clusters in the galaxy, while another is 2 billion years younger. A colleague of Bolte contends that the cluster called Palomar 12 is 5 billion years younger than most other globular clusters.

To explain the age differences among the globular clusters, astronomers are taking a second look at “renegade” theories. One such newly fashionable theory, first put forward by Richard Larson in the early 1970’s, argues that the halo of the Milky Way formed over a period of a billion or more years as hundreds of small gas clouds drifted about, collided, lost orbital energy, and finally collapsed into a centrally condensed elliptical system. Larson’s conception of a “lumpy and turbulent” protogalaxy is complemented by computer modeling done in the 1970’s by mathematician Alan Toomre, which suggests that closely interacting spiral galaxies could lose enough orbital energy to merge into a

single galaxy.

137. The passage is primarily concerned with discussing

(A)  the importance of determining the age of globular clusters in assessing when the Milky Way galaxy was formed

(B)  recent changes in the procedure used by astronomers to study the formation of the Milky Way galaxy

(C)  current disputes among astronomers regarding the size and form of the Milky Way galaxy

(D)  the effect of new discoveries regarding globular clusters on theories about the formation of the Milky Way galaxy (D)

(E)   the origin, nature, and significance of groups of stars known as globular clusters

我觉得这篇文章没有怎么说effect的问题，所以选不出答案。

我当时这两个也都错了．

137．主题句在第一句，New observations about the age of some globular clusters in our Milky Way galaxy have cast doubt on a long-held theory about how the galaxy was formed.第一段说主题－跟传统的不一样，第二段说传统理论，第三段说新观察到的证据．第四段将为什么

再看Ｄ选项

(D)  the effect of new discoveries regarding globular clusters on theories about the formation of the Milky Way galaxy

New observations about the age of some globular clusters in our Milky Way galaxy have cast doubt...在这里 have cast doubt＝have doubtful effect on

New observations = new discoveries

theory about how the galaxy was formed=theories about the formation of the Milky Way galaxy

从文章结构找主题句，我现在找起来感觉会容易些

140是很令人心烦的细节题

看第三段

 One of the clusters studied by Bolte is 2 billions years older than most other clusters in the galaxy, while another is 2 billion years younger. A colleague of Bolte contends that the cluster called Palomar 12 is 5 billion years younger than most other globular clusters.

这里面有两句同 most other clusters对比

2 billion years older than most other clusters
   

Palomar 12 is 5 billion years younger than most other globular clusters.

一个比大多数大2 billion，Palomar 12比大多数小5 billion ，就是那个比Palomar 12大７billion

Paloma 12 is approximately7 billion years younger than another cluster in the galaxy

要再看看其它为什么错了也可以

Ａ应该是than most other clusters ,不是any other

Ｂ不是the same age，是5 billion years younger

D 是Palomar 12，不是12 billion

Ｅ5 billion years younger ，不是
            2 billion years younger than most other clusters in the galaxy

这一题我也选错了。我是到今天做仔细分析后，找到一个这样的解释，个人认为是比较合理的：

原文第三段首先明确了MB的观察范围以及结果：However，the astronomer MB has found considerable variation in the ages of globular clusters.这里提及的globula clusters是指第一段里面的125 globular cluster distributed in a roughly spherical halo around the galactic nucleus.而P12 is 5B years younger than most other globula clusters.这里必须注意比较的范围：在银河系中心的globular clusters。选项中比较的对象变成了most other clusters in the galaxy,导致了比较对象的偏离，变成了全银河系的星团。这是从原文无法获得的信息。因此E是错误的。而C选项是another clusters in the galaxy，这个在前面的叙述中已经确认了以most globular clusters作为比较标准时，有一个是2B older的，而P12是5Byounger，因此C选项的正确性是肯定的。

当出现比较的时候，真的要十分小心，ETS对比较对象的考查。

个人观点，不知道OK否？欢迎赐教。