单选题 {{B}}Passage Two{{/B}}
What makes teenagers moody and impulsive? The answer used to be raging hormones plus a dearth of(短缺) life experiences. But three years ago this simple equation was blown apart by evidence from brain scans of strange goings-on behind the teenage forehead.
Till then, scientists had thought the brain's internal structure was fixed by the end of childhood. The new scans showed the brain's frontal cortex(皮层) thickening just before puberty(青春期), then slowly shrinking back to normal during the teenage years. Suddenly, the erratic huffiness(发怒) seemed to make sense: the teenage brain was a work in progress, a house in the process of being rewired.
Now comes more evidence of neural turmoil. According to psychologists in California, the speed with which youngsters can read the emotional expressions on people's faces dips suddenly at around the age of 11 or 12 and takes years to get back on track.
The latest study, like the brain scan research before it, is a welcome and necessary part of building up a picture of a typical teenage brain so that scientists can get a better handle on what might be happening in the mental illnesses that appear to be afflicting children and adolescents in ever greater numbers. But there are dangers.
Scientists still have no idea how to interpret the subtle changes seen in adolescent brain scans. Yet in the wrong hands, these findings could be used to justify hothousing, impulse control training and other dubious attempts to get the most out of malleable teenage brain cells. The science could also spark a new wave of moralising based on a perceived need to protect teenagers' evolving brain connections from evil or toxic influences.
Incredibly, some scientists have already suggested in the press that the brain scan evidence somehow proves that it is biologically bad for teenagers to play video games or lie on the couch watching MTV. A hundred years, ago one well-known "expert" urged teenage boys to drink six to eight glasses of hot water a day to flush impure thoughts from their bodies. Have we really learned so little?
单选题 In the past it was thought that teenagers were moody and impulsive because of______.
【正确答案】 B
【答案解析】第1段的第2句话The answer used to be raging hormones plus a dearth of life experience(答案过去一直是由于易怒荷尔蒙的存在和缺乏生活经历所致)就是该题解题的关键信息。
单选题 In the last line, paragraph two, "a house in the process of being rewired" indicates that ______.
【正确答案】 C
【答案解析】文中提到“the teenage brain was a work in progress，a house in the process of being rewired”十几岁青少年大脑的发育是一个进展中的过程，就像一所重铺电线的房子一样。所以重铺线路的房子只是用来比喻大脑发展的一个阶段，所以选C。
单选题 From the passage we can learn that ______.
【正确答案】 A
【答案解析】见第2段最后一句话中的the teenage brain was a work in progress，a house in the process of being rewired(少年人的脑子正在发育，是一个处于正在改造变化之中的结构体)是答案所在。
单选题 The latest study is very helpful in that ______.
【正确答案】 C
【答案解析】该题解题所需的信息在第4段中的so that scientists can get a better handle on what might be happening in the mental illness这一部分。
单选题 According to paragraph five, which of the following statements reflects the present medical reality?
【正确答案】 D
【答案解析】选项D同本文第5段的第一句话意思完全相同，只是利用另外一种说法对该句的重述，所以本题的答案应为D。
单选题 The author's attitude towards the findings of teenagers' brain scans can be concluded as ______.
【正确答案】 A
【答案解析】这是一个作者态度题。本题可以通过对整篇文章的理解推断出来。在本文中作者首先描述脑扫描的结果有助于科学家更好地理解青少年中出现的精神失常现象，但同时又指出目前还无法解释清楚脑扫描结果，所以提醒人们不要仓促使用扫描结果，由此可以看出作者的态度应该是cautious(慎重的)。