Paragraph 4 If social living carries a heightened risk of infection, then the larger the group, the greater the risk. This prediction holds for cliff swallows, which pack their nests side by side in colonies composed of anywhere from a handful of birds to several thousand pairs. The more swallows nesting together, the greater the chance that at least one bird will be infested with swallow bugs, which can then readily spread from one nest to another.
animals can. Solitary animals can hide from predators more easily than groups of animals can. Solitary animals do not need to spend time and energy competing for social status. Solitary animals do not need large quantities of food to survive. 细节题：
4. According to paragraph 3 which of the following is likely to increase when animals live with other members of their species rather than alone reproductive success unpredictable behavior among males resistance to disease competition for food 细节题： 回到文中可以看到主要内容是：sociality has two other potential disadvantages. The first is heightened competition for food；The second is increased vulnerability to parasites and disease, which plague social species of all sorts. 回到选项只有 D 是对的
5. In paragraph 3 why does author discuss "honeybees warming their hives in response to an infestation by a fungal pathogen"? To give an example of how living in groups benefits animals To illustrate how social species combat parasites and disease To indicate that worker bees are the most active in fighting parasites and disease To demonstrate that avoiding a disadvantage of social living can carry its own costs 修辞目的题：
3. Which of the following is associated in paragraph 3 with reproductive interference in social animals Females being pushed away from their food by hungry males Breeding males losing their mates to more attractive males Parasites and disease infecting the eggs of breeding females Females warming their habitats to care a fungal pathogen 细节题： 定位到第一句，然后看下一句：Breeding males that live in close association with more attractive rivals may lose their mates to these individuals. 这句话的主干是 breeding males lose their mates. 直接与 B 是对应的。
找到定位局，其下一句是：Among most social species, animals have to expend time and energy competing for social status. 和 C 是同义替换。
Paragraph 3 Social groups also offer opportunities for reproductive interference. Breeding males that live in close association with more attractive rivals may lose their mates to these individuals. In addition, sociality has two other potential disadvantages. The first is heightened competition for food, which occurs in animals as different as colonial fieldfares (a kind of songbird) and groups of lions, whose females are often pushed from their food by hungry males. The second is increased vulnerability to parasites and disease, which plague social species of all sorts. While it is true that some social animals have evolved special responses designed to combat parasites and disease, those responses can only reduce, but cannot totally eliminate, the damage caused by those threats, and the responses may even carry their own costs. Thus, honeybees wafollowing can be inferred from paragraph 2 as a reason for saying that under
some conditions a solitary life is superior to a more social life? Solitary animals can compete more successfully against animals of other species than social
2014-03-16 01
Costs and Benefits of Social Life
Many think that the reason so many animals live with others of their species is that social creatures are higher up the evolutionary scale and so are better adapted and leave more offspring than do animals that live solitary lives. However, in each and every species, generation after generation, relatively social and relatively solitary types compete unconsciously with one another in ways that determine who leaves more offspring on average. In some species, the more social individuals have won out, but in a large majority, it is the solitary types that have consistently left more surviving descendants on average.
hives in response to an infestation by a fungal pathogen, which apparently helps kill the heat-sensitive fungus, but at the price of time and energy expended by the heat-producing workers. 2. The word "potential" in the passage is closest in meaning to possible serious common related 单词题： 潜在地 选 A