未知题型 Until recently, scientists did not know of a close verte-brate analogue to the extreme form. of altruism abserved ineusocial insects like ants and bees, whereby individualscooperate, 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 Heterocephalusglaber, 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 reproducingfemalE.Other adult female mole rats neither ovulate norbreeD.The queen of the largest member of the colony, andshe maintains her breeding status through a mixture ofbehavioral and, presumably, chemical control. Queens have(15) been long-lived in captivity, and when they die or areremoved from a colony one sees violent fighting for breed-ing status among the larger remaining females, leading to atakeover by a new queen.Eusocial insect societies have rigid caste systems, each(20)insects’s role being defined by its behavior,body shape, andphysiology. In naked mole rat societies, on the other hand,differences in behavior. are related primarily to reproductivestatus (reproduction being limited to the queen and a fewmales), body size, and perhaps agE.Smaller nonbreeding(25) members, both male and female, seem to participate pri-marily in gathering food, transporting nest material, andtunneling. Larger nonreaders are active in defending thecolony 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 performsa task, regardless of its agE.Cooperative breeding has evolved many times in verte-brates, but unlike naked mole rats, most cooperativelybreeding vertebrates (except the wild dog, Lycaon pictus)(35) are dominated by a pair of breeders rather than by a singlebreeding femalE.The division of labor within social groupsis less pronounced among other vertebrates than amongnaked mole rats, colony size is much smaller, and matingby subordinate females may not be totally suppressed,(40) whereas in naked mole rat colonies subordinate females arenot sexually active, and many never breeD.Which of the following most accurately states the main idea of the passage?A.Naked mole rat colonies are the only known examples of cooperatively breeding vertebrate societies.B.Naked mole rat colonies exhibit social organization based on a rigid caste system.C.Behavior. in naked mole rat colonies may well be a close vertebrate analogue to behavior. in eusocial insect societies.D.The mating habits of naked mole rats differ from those of any other vertebrate species.E.The basis for the division of labor among naked mole rats is the same as that among eusocial insects.

未知题型 The passage supports which of the following inferences about breeding among Lycaon pictus?A.The largest female in the social group does not maintain reproductive status by means of behavioral control.B.An individual’s ability to breed is related primarily to its rate of growth.C.Breeding is the only task performed by the breeding femalE.D.Breeding in the social group is not cooperativE.E.Breeding is not dominated by a single pair of dogs.

单项选择题 下列关于管理层次和管理幅度之间关系的说法中，错误的是（ ）。