①In his book The Tipping Point, Malcolm Gladwell argues that “social epidemics” are driven in large part by the actions of a tiny minority of special individuals, often called influentials, who are unusually informed, persuasive, or well connected. The idea is intuitively compelling, but it doesn’t explain how ideas actually spread.

②The supposed importance of influentials derives from a plausible-sounding but largely untested theory called the “two-step flow of communication”: Information flows from the media to the influentials and from them to everyone else. Marketers have embraced the two-step flow because it suggests that if they can just find and influence the influentials, those select people will do most of the work for them. The theory also seems to explain the sudden and unexpected popularity of certain looks, brands, or neighborhoods. In many such cases, a cursory search for causes finds that some small group of people was wearing, promoting, or developing whatever it is before anyone else paid attention. Anecdotal evidence of this kind fits nicely with the idea that only certain special people can drive trends.

③In their recent work, however, some researchers have come up with the finding that influentials have far less impact on social epidemics than is generally supposed. In fact, they don’t seem to be required at all.

④The researchers’ argument stems from a simple observation about social influence: With the exception of a few celebrities like Oprah Winfrey—whose outsize presence is primarily a function of media, not interpersonal, influence—even the most influential members of a population simply don’t interact with that many others. Yet it is precisely these non-celebrity influentials who, according to the two-step-flow theory, are supposed to drive social epidemics, by influencing their friends and colleagues directly. For a social epidemic to occur, however, each person so affected must then influence his or her own acquaintances, who must in turn influence theirs, and so on; and just how many others pay attention to each of these people has little to do with the initial influential. If people in the network just two degrees removed from the initial influential prove resistant, for example, the cascade of change won’t propagate very far or affect many people.

⑤Building on this basic truth about interpersonal influence, the researchers studied the dynamics of social influence by conducting thousands of computer simulations of populations, manipulating a number of variables relating to people’s ability to influence others and their tendency to be influenced. They found that the principal requirement for what is called “global cascades”—the widespread propagation of influence through networks—is the presence not of a few influentials but, rather, of a critical mass of easily influenced people. 

1.By citing the book The Tipping Point, the author intends to _________

A analyze the consequences of social epidemics.

B discuss influentials’ function in spreading ideas.

C exemplify people’s intuitive response to social epidemics.

D describe the essential characteristics of influentials.

解析：选B。B目的意图题。根据题目定位到第一段，可知《引爆点》中认为“社会流行”在很大程度上是由一小撮特殊个体（有影响力的人）的行为推动的，然后作者指出，这看起来很有说服力，但并没有解释观点实际上是如何传播的。可知作者欲引出对“有影响力的人在传播观点中究竟是如何起作用的”的探讨，故选B。

2.The author suggests that the “two-step-flow theory” _________

A serves as a solution to marketing problems.

B has helped explain certain prevalent trends.

C has won support from influentials.

D requires solid evidence for its validity.

解析：选D。D细节理解题。根据题目定位到第二段，根据第一句可知作者认为有影响力的人的重要性听起来貌似有理，但在很大程度上未经验证，故选D。

3.What the researchers have observed recently shows that _________

A the power of influence goes with social interactions.

B interpersonal links can be enhanced through the media.

C influentials have more channels to reach the public.

D most celebrities enjoy wide media attention.

解析：选A。A推理判断题。根据researchers和observed定位到第四段，可知社会流行的发生需要每个受影响的人都必须接着影响自己的熟人，这些熟人必须再影响他们的熟人，如此循环下去；有多少人会关注这些人与最初的有影响力的人关系不大。可推知社会流行的影响力是伴随着社会交往发生的，故选A。

4.The underlined phrase “these people” in Paragraph 4 refers to the ones who _________

A stay outside the network of social influence.

B have little contact with the source of influence.

C are influenced and then influence others.

D are influenced by the initial influential.

解析：选C。C细节理解题。根据题目定位到第四段，可知要使一种社会流行风潮发生，每个受影响的人都必须接着影响自己的熟人，这些熟人必须再影响他们的熟人，如此循环下去；有多少人会关注这些人与最初的有影响力的人关系不大。其中的“这些人”指的就是前面分句中：被影响然后接着影响他人的人。故选C。

5.What is the essential element in the dynamics of social influence?

A The eagerness to be accepted.

B The impulse to influence others.

C The readiness to be influenced.

D The inclination to rely on others.

解析：选C。C细节理解题。根据题目定位到第五段，根据principal requirement和the presence...of a critical mass of easily influenced people可知最主要的要求是有一大批容易受影响的人存在，故选C。