单选题 The teenager is a uniquely human phenomenon.
Adolescents are known to be moody, insecure, argumentative, restless, impulsive, impressionable, reckless and rebellious. Teenagers are also characterized by odd sleeping patterns, sudden burst of emotion, bullying, and snobbish behavior. So what could be the possible benefit of the teenage phase?
Most other animals—apes and human ancestors included—skip that stage altogether, developing rapidly from infancy to full adulthood. Humans, in contrast, have a very puzzling four-year gap between sexual maturity and prime reproductive age. Anthropologists disagree on when the teenage phase first evolved.
There are a variety of current explanations for the existence of teenagers. Some believe that we need longer for our large brains to develop. Other explanations suggest that a teenage phase allows kids to learn about complex social behavior and other difficult skills, or that it is even required to develop coordinated bipedal bodies adapted to travelling long distances.
Scientists once thought that the brain"s internal structure was fixed at the end of childhood, and teenage behavior was blamed on raging hormones and a lack of experience. Then researchers discovered that the brain undergoes significant changes during adolescence.
According to many recent studies, teen brains really are unique. Though many brain areas mature during childhood, others mature later—such as the frontal and parietal lobes (顶叶), responsible for planning and self-control.
Other studies have shown that teens fail to see the consequences of their actions, and that sudden increases in nerve connectivity in teen brains may make it difficult for teenagers to read social situations and other people"s emotions.
One study in 2004 showed that teens have less brain activity in areas responsible for motivation and risk assessment, perhaps explaining why they are more likely to take part in risky activities such as abusing drugs and alcohol, develop a hard-to-kick smoking habit or indulge in under-age sex.
Teenage pregnancies and rising rates of sexually transmitted diseases among teens are big problems—especially because today"s teen generation is the biggest the world has seen. a 2003 UN report revealed that one in five people were between 10 and 19, a total of 1.2 billion people.
But not everyone agrees on the best way to tackle the problem. Some believe that comprehensive sex education is the key, while others argue for abstinence (禁欲) only education courses.
单选题 According to the author, the teenager is a unique human phenomenon because ______.
【正确答案】 A
【答案解析】[考点] 细节推断
此题考查考生根据文章具体内容进行细节推断的能力。问题问：作者认为，青春期是一种特殊的人类现象，因为______。文章第一段指出，青春期是人类特有的一种现象。第二段详细描述了青春期独一无二的特征，如古怪的睡眠方式、感情冲动、恃强欺弱、自命不凡等。第三段提出，许多其他动物，包括猿猴和人类祖先，都越过了青春期而迅速地从婴儿期进入成年期。由此可以判断，作者认为，青春期是一种特殊的人类现象，因为它所具有的特点是人类在其他发展阶段所没有的。所以，本题正确答案是A。
干扰项B：研究人员无法解释青春期最早是从何时演变而来；干扰项C：对于人类来说，青春期是一个非常有益的阶段；干扰项D：青少年能够了解复杂的社会行为。这三个选项的内容与原文不符。
单选题 Which of the following is NOT true according to the passage?
【正确答案】 C
【答案解析】[考点] 正误判断
此题考查考生根据文章具体内容进行正误判断的能力。问题问：四个选项中，哪一种说法不正确?文章第四段提出，对于青春期，目前有各种不同的解释。有人认为，我们需要较长的时期让大脑发育；其他人认为，青春期可以使孩子了解复杂的社会行为以及其他难以掌握的技能。但文章没有提到，青春期是当青少年性成熟时开始的。所以，本题正确答案是C。
干扰项A：青春期可以让孩子了解难以掌握的技能；干扰项B：青春期可以让孩子了解社会行为；干扰项D：青春期是大脑发展必不可少的一个阶段。
单选题 The adolescents are poor at self-control partly because ______.
【正确答案】 A
【答案解析】[考点] 细节推断
此题考查考生根据文章具体内容进行细节推断的能力。问题问：青少年自控力比较差，部分原因是______。文章第六段指出，青少年的大脑很独特：虽然大脑的很多区域在儿童时期就发育成熟，但其他区域，比如负责计划和自控的区域，却成熟较晚。由此可推断出，青少年缺乏自控力，部分原因是，负责自控力的大脑区域发育不够成熟。所以，本题正确答案是A。
干扰项B：他们的大脑经历了重大变化。这一内容与原文不符。干扰项C：他们的大脑还没有复杂到可以控制自己的行为。干扰项D：没有人教育他们要学会自控。选项C和选项D的内容原文没有提及。
单选题 The word "read" (Para. 7) is closest in meaning to ______.
【正确答案】 B
【答案解析】[考点] 词语含义
此题考查考生根据文章具体内容判断词语含义的能力。文章第七段指出，其他研究表明，青少年意识不到其行为后果，而大脑中的神经连通性能突然增加，可能会使他们难以“read”社会环境和他人的感情。由此可以判断，青少年对社会环境和他人的感情不能很好地解读。所以，本题正确答案是B：理解。
干扰项A：意识到；干扰项C：解释；干扰项D：证明。
单选题 What is a hard-to-kick habit (Para. 8), according to the text?
【正确答案】 D
【答案解析】[考点] 语义判断
此题考查考生根据文章具体内容进行语义判断的能力。问题问：文章第八段中的“a hard-to-kick habit”是什么含义。文章第八段提出，2004年的一项调查表明，青少年的大脑在负责动机和危险判断的区域活动较少，这或许可以解释为什么青少年更有可能参加一些危险性的活动，如吸毒和酗酒，养成______的抽烟习惯，或沉溺于未成年性行为中。依据上下文，hard-to-kick具有的含义与indulge in相似，都表示难以自拔、难以摆脱。由此可以判断，“a hard-to-kick habit”指的是难以摆脱的习惯。所以，本题正确答案是D。
干扰项A：需要狠狠用脚去踢的习惯；干扰项B：不容易用脚去踢的习惯；干扰项C：很久养成的习惯。
单选题 Pregnancies and sexually transmitted diseases in teenagers are considered big problems because ______.
【正确答案】 A
【答案解析】[考点] 细节推断
此题考查考生根据文章具体内容进行细节推断的能力。问题问：青少年怀孕和青少年性传播疾病被认为是个大问题，因为______。文章第九段指出，青少年怀孕以及患性传播疾病概率的增加是个大问题，特别是因为这一代青少年是历史上人口最为庞大的一代，2003年一项联合国报告表明，全球20%的人口年龄介于10～19岁之间，总人数为12亿。由此可以判断，青少年怀孕和青少年性传播疾病是个大问题，因为这一代青少年人口最为庞大。所以，本题正确答案是A。
干扰项B：青少年是独特的一代；干扰项C：青少年更敢于冒险；干扰项D：青少年自控力较差。