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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 (com-
(5)pact 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
(10)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
(15)200 million years) when a spherical cloud of gas col-
lapsed 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.
(20) 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
(25)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,
(30)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
(35)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.
143. The author of the passage puts the word “renegade” (line 29) in quotation marks most probably in order to
(A) emphasize the lack of support for the theories in question
(B) contrast the controversial quality of the theories in question with the respectable character of their formulators
(C) generate skepticism about the theories in question
(D) ridicule the scientists who once doubted the theories in question (E)
(E) indicate that the theories in question are no longer as unconventional as they once seemed
The best answer is E. To describe a theory as “renegade” is to suggest that it is unconventional.
However, the author puts the word “renegade” in quotation marks (line 29) when using it to
describe theories that, the author says, are “newly fashionable” (line 29). The use of quotation
marks with this word in this way serves to indicate that the theories in question are no longer as
unconventional as they once seemed. There is nothing in the passage to suggest that any of the
other choices describe goal of the author.
GMAT里引号作用记得有2个，一个是反语讽刺，一个是强调，这里为啥不能选D哪？哪里体现这个理论是“newly fashionable”了？renegade不是变节者得意思吗？ | 
