阅读理解 America has seen a drop in crime rates that in earlier years would have been universally viewed as impossible. The overall crime rate has plummeted by 45% since peaking in 1991 and by 13% just since 2007—counterintuitively continuing to drop through the recession and sharp spike in unemployment.
Since 1991, according to FBI data, the number of violent crimes has fallen 36% nationally and 64% in the nation's largest cities. And in New York and Los Angeles, the nation's two largest cities , it has fallen even further. Property crime has also become increasingly rare. Incredibly, in New York City, car thefts have plunged 94% in the past two decades.
How is this possible? In the mid-1990s, few saw this decline coming, and many warned that crime would surge once again as teens of that era grew into young adults. Today, criminologists still differ on what has caused the nationwide turnaround in crime rates and why those dire predictions never came to pass. But crime-fighting technology, better policing, aging societies, growing urban populations and declining usage of hard drugs are widely cited. For many Americans, the drop in crime has resulted not only in a much higher quality of life but in a reduced economic burden as well. Safer cities generally mean stronger urban economies.
In the same category of big surprises, teen-pregnancy rates have fallen to their lowest level in more than 30 years, according to the widely respected Guttmacher Institute. They have declined 51% from their 1990 peak, based on the latest available data, and the teenage birthrate is down 43% from that year's level. Today, fewer teens are becoming pregnant and becoming mothers than at any point since reliable data has been collected by the National Center for Health Statistics. This is also true for women in the 20-to-24 age group. To put it mildly, there were very few predictions to this effect a generation ago. In addition, overall birthrates in the U. S. have turned up for the first time since 2007—including for children born to women in a college education—to just shy of 4 million.

单选题 16.What can we learn from the first paragraph?

【正确答案】 C

【答案解析】[A]项对应原文：The overall crime rate has plummeted by 45％since peaking in 1991and by 13％just since 2007．原文说的是自2007年起总体犯罪率降低13％，而非选项中说的保持13％，故该项错误。[B]项前半句是正确的，错在后半句的and other countries，因为本文讨论的是美国的犯罪率，并未出现其他国家。[C]项对应原文：The overall crime rate has plum—meted by 45％since peaking in 1991…其中peaking表示顶点，即1991年犯罪率达到顶点，该项是本句话的同义替换，故为答案。选项[D]对应原文：．．．drop through the recession and sharpspike in unemployment．原文提到的一个关键词是drop，而非该项的rose，故该项错误。

单选题 17.We can conclude from the second paragraph that______.

【正确答案】 D

【答案解析】选项[A]对应原文：Property crime has also become increasingly rare．文章提到property crime是越来越少而不是越来越多，故该项错误。[B]项对应原文：Since 1991，according toFBI data，the number of violent crimes has fallen 36％nationally and 64％in the nation’s largestcities．通过阅读该句可以知道，36％是全国的数据而非最大城市的数据，最大城市的降幅是64％。故该项错误。选项[C]对应原文：Incredibly，in New York City，car thefts have plunged94％in the past two decades．表面看该项和原文几乎是一样的，不一样的地方是drop to 94％和原文的plunged 94％，其中drop=plunge。plunge一词原意是“跳水”，引申为“缩水，缩小，减少”的意思，而该项设置的陷阱在于介词to，原文说“plunged 94％减少94％”，而该项说的却是“dropped to 94％减少至94％”，故错误。选项[D]对应该段第一句话：Since 1991，according toFBI data，the number of violent crimes has fallen 36％nationally and 64％in the nation’s largestcities．由此可知，全国暴力犯罪率降低，尤其是大城市，故该项是正确的。

单选题 18.Which one is NOT the possible reason of the dropping crime rates?

【正确答案】 B

【答案解析】根据题干定位到原文第三段第三、四句：Today，criminologists still differ on what hascaused the nationwide turnaround in crime rates and why those dire predictions never came to pass．But crime—fighting technology，better policing，aging societies，growing urban populations and decli—ning usage of hard drugs are widely cited．大意为：对于犯罪率降低的原因犯罪学家观点不一致，但是……，要特别注意But一词后面的内容，But后面列出一系列短语，并说道它们被广泛引述，也就是说广泛认为这些是原因。而选项中只有[B]Better education没有出现，故该项为答案。

单选题 19.What can we infer from the last paragraph?

【正确答案】 B

【答案解析】[A]项对应最后一句：In addition，overall birthrates in the U．S．have turned up forthe first time since 2007—including for children born to women in a college education--to just shy of4 million．关键词是turned up，即上升的意思，而非下滑，故该项错误。[B]项对应倒数第二句：To put it mildly，there were very few predictions to this effect a generation ago．其中this effect指代上文提到的“年轻女孩的怀孕率和生育率下降了”，故该项正确。[C]项属于偷换概念。原文说的下降43％的是teenage birthrate(青少年生育率)，而非该项说的teen-pregnancy rates(青少年怀孕率)，故该项错误。[D]项对应倒数第三句：This is also true for women in the 20-to-24 age group．原文并未提到任何关于women above 24(24岁以上女性)的内容，故该项属于无中生有。

单选题 20.The best title for the text may be______.

【正确答案】 A

【答案解析】本文前三段讨论美国犯罪率下降，最后一段讨论青少年怀孕率也同时下降；同时原文第三段首句指出：How is this possible?In the mid-1990s，few saw this decline coming，andmany warned that crime would surge once again as teens of that era grew into young adults．最后一段倒数第二句又指出：To put it mildly，there were very few predictions to this effect a generationago．文中两次提到犯罪率和青少年怀孕率下降是很多人没有预测到的，其中选项[A]中的surprisingly down可以体现出这点，故选项[A]正确。选项[B]中的teen-pregnancy rate increases明显错误。选项[C]中的in the future文章没有讨论。选项[D]中的has been predicted与原文不符。