21. According to the first paragraph, peer pressure often emerges as
- A. a supplement to the social cure.
- B. a stimulus to group dynamics.
- C. an obstacle to social progress.
- D. a cause of undesirable behaviors.
答案：D
答案句：Come on – Everybody's doing it. That whispered message, half invitation and half forcing, is what most of us think of when we hear the words peer pressure. It usually leads to no good – drinking, drugs and casual sex.
参考译文：“来吧——大家都在这么做。”这句耳语，半是邀请半是强迫，是我们大多数人听到“同伴压力”这个词时所想到的。它通常不会带来什么好事——酗酒、吸毒和随意性行为。
定位线索：题干“According to the first paragraph”定位到第1段；文中“It usually leads to no good – drinking, drugs and casual sex”对应选项D“a cause of undesirable behaviors”（“leads to no good”对应“cause of undesirable behaviors”）。
解析：题干问第一段中同伴压力通常表现为什么。答案句直接说“它通常导致不好的事——酗酒、吸毒和随意性行为”，即不良行为的原因，对应D。A“社会治疗的补充”是后文内容，B“群体动力的刺激”是Rosenberg的观点，C“社会进步的障碍”文中未提，均无中生有。
22. Rosenberg holds that public-health advocates should
- A. recruit professional advertisers.
- B. learn from advertisers’ experience.
- C. stay away from commercial advertisers.
- D. recognize the limitations of advertisements.
答案：B
答案句：Rosenberg argues convincingly that public-health advocates ought to take a page from advertisers, so skilled at applying peer pressure.
参考译文：罗森伯格令人信服地论证道，公共卫生倡导者应该向广告商学习，他们如此擅长运用同伴压力。
定位线索：题干“Rosenberg holds that public-health advocates should”对应答案句“public-health advocates ought to take a page from advertisers”；文中“take a page from”对应选项B“learn from advertisers' experience”（“take a page from”意为“借鉴、学习”）。
解析：题干问Rosenberg认为公共卫生倡导者应该怎么做。答案句明确说“应该向广告商学习”，即借鉴广告商的经验，对应B。A“招募专业广告商”偷换概念，C“远离商业广告商”与原文相反，D“认识到广告的局限”文中未提。
23. In the author’s view, Rosenberg’s book fails to
- A. adequately probe social and biological factors.
- B. effectively evade the flaws of the social cure.
- C. illustrate the functions of state funding.
- D. produce a long-lasting social effect.
答案：A
答案句：Join the Club is filled with too much irrelevant detail and not enough exploration of the social and biological factors that make peer pressure so powerful.
参考译文：《加入俱乐部》充斥着太多无关的细节，并且对使同伴压力如此强大的社会与生物因素探索不足。
定位线索：题干“Rosenberg's book fails to”对应答案句“not enough exploration of the social and biological factors”；文中“not enough exploration”对应选项A“adequately probe social and biological factors”（“not enough”对应“fails to adequately probe”）。
解析：题干问作者认为Rosenberg的书未能做到什么。答案句说“对使同伴压力强大的社会与生物因素探索不足”，即未能充分探究这些因素，对应A。B“有效规避社会治疗的缺陷”文中说“最明显的缺陷是效果不持久”，并非规避，C“说明州资金的功能”是例子细节，D“产生长期社会效果”是书中内容而非书的失败之处，答非所问。
24. Paragraph 5 shows that our imitation of behaviors
- A. is harmful to our networks of friends.
- B. will mislead behavioral studies.
- C. occurs without our realizing it.
- D. can produce negative health habits.
答案：C
答案句：This is a subtle form of peer pressure: we unconsciously imitate the behavior we see every day.
参考译文：这是一种微妙的同伴压力形式：我们无意识地模仿每天看到的行为。
定位线索：题干“Paragraph 5 shows that our imitation of behaviors”对应答案句“we unconsciously imitate the behavior”；文中“unconsciously”对应选项C“occurs without our realizing it”（“unconsciously”同义改写为“without our realizing it”）。
解析：题干问第5段表明我们对行为的模仿如何。答案句说“我们无意识地模仿每天看到的行为”，“无意识”即“没有意识到”，对应C。A“对朋友网络有害”文中说积极和消极习惯都传播，未说有害，B“误导行为研究”无中生有，D“能产生消极健康习惯”是部分事实，但题干问的是模仿的特点而非结果，且C更直接。
25. The author suggests in the last paragraph that the effect of peer pressure is
- A. harmful.
- B. desirable.
- C. profound.
- D. questionable.
答案：D
答案句：Far less certain, however, is how successfully experts and bureaucrats can select our peer groups and steer their activities in virtuous directions. It's like the teacher who breaks up the troublemakers in the back row by pairing them with better-behaved classmates. The tactic never really works. And that's the problem with a social cure engineered from the outside: in the real world, as in school, we insist on choosing our own friends.
参考译文：然而，远不那么确定的是，专家和官僚们能在多大程度上成功地选择我们的同伴群体，并引导他们的活动走向良善方向。这就像老师把后排捣蛋鬼与表现更好的同学配对来拆散他们。这种策略从未真正奏效。这就是从外部设计的社会治疗的问题所在：在现实世界中，就像在学校里一样，我们坚持选择自己的朋友。
定位线索：题干“The author suggests in the last paragraph that the effect of peer pressure is”对应答案句“Far less certain”和“The tactic never really works”；文中“Far less certain”对应选项D“questionable”（“不确定”同义改写为“可疑的、有问题的”）。
解析：题干问作者在最后一段暗示同伴压力的效果如何。答案句说“远不那么确定”“这种策略从未真正奏效”，表明作者对效果持怀疑态度，对应D“可疑的”。A“有害的”过于绝对，B“可取的”与原文相反，C“深远的”文中虽提到同伴群体影响大，但最后一段强调的是不确定性，且题干问的是“效果”而非“影响”，D更准确。