| Passage 27
Until recently, scientists did not know of a close verte-
brate analogue to the extreme form of altruism abserved in
eusocial insects like ants and bees, whereby individuals
cooperate, sometimes even sacrificing their own oppor-
( 5) tunities to survive and reproduce, for the good of others.
However, such a vertebrate society may exist among under-
ground colonies of the highly social rodent Heterocephalus
glaber, the naked mole rat.
A naked mole rat colony, like a beehive, wasp’s nest, or
(10) termite mound, is ruled by its queen, or reproducing
female. Other adult female mole rats neither ovulate nor
breed. The queen of the largest member of the colony, and
she maintains her breeding status through a mixture of
behavioral and, presumably, chemical control. Queens have
(15) been long-lived in captivity, and when they die or are
removed from a colony one sees violent fighting for breed-
ing status among the larger remaining females, leading to a
takeover by a new queen.
Eusocial insect societies have rigid caste systems, each
(20)insects’s role being defined by its behavior,body shape, and
physiology. In naked mole rat societies, on the other hand,
differences in behavior are related primarily to reproductive
status (reproduction being limited to the queen and a few
males), body size, and perhaps age. Smaller nonbreeding
(25) members, both male and female, seem to participate pri-
marily in gathering food, transporting nest material, and
tunneling. Larger nonreaders are active in defending the
colony and perhaps in removing dirt from the tunnels.
Jarvis’ work has suggested that differences in growth rates
(30)may influence the length of time that an individual performs
a task, regardless of its age.
Cooperative breeding has evolved many times in verte-
brates, but unlike naked mole rats, most cooperatively
breeding vertebrates (except the wild dog, Lycaon pictus)
(35) are dominated by a pair of breeders rather than by a single
breeding female. The division of labor within social groups
is less pronounced among other vertebrates than among
naked mole rats, colony size is much smaller, and mating
by subordinate females may not be totally suppressed,
(40) whereas in naked mole rat colonies subordinate females are
not sexually active, and many never breed.
166. One function of the third paragraph of the passage is to
(A) state a conclusion about facts presented in an earlier paragraph
(B) introduce information that is contradicted by information in the fourth paragraph
(C) qualify the extent to which two previously mentioned groups might be similar
(D) show the chain of reasoning that led to the conclusions of a specific study
(E) demonstrate that, of three explanatory factors offered, two may be of equal significance
D选项为什么不对呢，第三段是为了支持第一段这个主题啊？
Passage 35
Two divergent definitions have dominated sociologists’
discussions of the nature of ethnicity. The first emphasizes
the primordial and unchanging character of ethnicity. In
this view, people have an essential need for belonging that
(5) is satisfied by membership in groups based on shared
ancestry and culture. A different conception of ethnicity
de-emphasizes the cultural component and defines ethnic
groups as interest groups. In this view, ethnicity serves as
a way of mobilizing a certain population behind issues
(10) relating to its economic position. While both of these
definitions are useful, neither fully captures the dynamic
and changing aspects of ethnicity in the United States.
Rather, ethnicity is more satisfactorily conceived of as a
process in which preexisting communal bonds and common
(15) cultural attributes are adapted for instrumental purposes
according to changing real-life situations.
One example of this process is the rise of participation
by Native American people in the broader United States
political system since the Civil Rights movement of the
(20)1960’s. Besides leading Native Americans to participate
more actively in politics (the number of Native American
legislative officeholders more than doubled), this movement
also evoked increased interest in tribal history and traditional
culture. Cultural and instrumental components of
(25 )ethnicity are not mutually exclusive, but rather reinforce
one another.
The Civil Rights movement also brought changes in the
uses to which ethnicity was put by Mexican American
people. In the 1960’s, Mexican Americans formed
(30) community-based political groups that emphasized ancestral
heritage as a way of mobilizing constituents. Such emerg-
ing issues as immigration and voting rights gave Mexican
American advocacy groups the means by which to promote
ethnic solidarity. Like European ethnic groups in the
(35) nineteenth-century United States, late-twentieth-century
Mexican American leaders combined ethnic with contem-
porary civic symbols. In 1968 Henry Censors, then mayor
of San Antonio, Texas, cited Mexican leader Benito Juarez
as a model for Mexican Americans in their fight for con-
(40) temporary civil rights. And every year, Mexican Americans
celebrate Cinco de Mayo as fervently as many Irish
American people embrace St. Patrick’s Day (both are major
holidays in the countries of origin), with both holidays
having been reinvented in the context of the United States
and linked to ideals, symbols, and heroes of the United
States
218. Which of the following best states the main idea of the passage?
(A) In their definitions of the nature of ethnicity, sociologists have underestimated the power
of the primordial human need to belong.
(B) Ethnicity is best defined as a dynamic process that combines cultural components with
shared political and economic interests.
(C) In the United States in the twentieth century, ethnic groups have begun to organize in
order to further their political and economic interests.
(D) Ethnicity in the United States has been significantly changed by the Civil Rights
movement.
(E) The two definitions of ethnicity that have dominated sociologists discussions are
incompatible and should be replaced by an entirely new approach.
B选项中的economic interests 是从哪里体现的呢，我怎么找不到呢，谢谢！ | 
