21. The Romans buried the nails probably for the sake of ____
- A. saving them for future use.
- B. keeping them from rusting.
- C. letting them grow in value.
- D. hiding them from the locals.
答案：D
答案句：The likely explanation is that the withdrawal was rushed, and they didn't want the local Caledonians getting their hands on 10 tons of weapon-grade iron. The Romans buried the nails so deep that they would not be discovered for almost two millennia.
Late
参考译文：可能的解释是，撤退很匆忙，他们不想让当地的喀里多尼亚人得到10吨武器级的铁。罗马人把钉子埋得如此之深，以至于它们几乎两千年都不会被发现。
定位线索：题干“The Romans buried the nails probably”→答案句“The likely explanation is that the withdrawal was rushed, and they didn't want the local Caledonians getting their hands on 10 tons of weapon-grade iron”；文中“didn't want the local Caledonians getting their hands on”对应选项D“hiding them from the locals”。
解析：题干问罗马人埋钉子的原因，答案句直接给出解释：不想让当地人得到武器级铁，即把钉子藏起来不让当地人发现。选项D“hiding them from the locals”是对“didn't want the local Caledonians getting their hands on”的同义转述。选项A“saving them for future use”无中生有，文中未提未来使用；选项B“keeping them from rusting”无中生有，文中未提防锈；选项C“letting them grow in value”无中生有，文中未提增值。
22. The example of early 17th-century Virginians is used to ____
- A. highlight the thriftiness of early American colonists.
- B. illustrate the high status of blacksmiths in that period.
- C. contrast the attitudes of different civilisations towards nails.
- D. show the preciousness of nail-making technology at that time.
答案：D
答案句：Later civilisations would value the skilled blacksmith's labour in a nail even more than the raw material. As Roma Agrawal explains in her new delightful book Nuts and Bolts, early 17th-century Virginians would sometimes bum down their homes if they were planning to relocate. This was an attempt to recover the valuable nails, which could be reused after sifting the ashes. The idea that one might bum down an entire house just to reclaim the nails underlines how scarce, costly and valuable the simple-seeming technology was.
参考译文：后来的文明对钉子中熟练铁匠劳动的重视甚至超过原材料。正如Roma Agrawal在她令人愉快的新书《螺母与螺栓》中所解释的，17世纪早期的弗吉尼亚人有时会在计划搬迁时烧毁自己的房子。这是为了回收宝贵的钉子，这些钉子可以在筛过灰烬后重新使用。一个人为了回收钉子而烧毁整栋房子的想法，突显了这种看似简单的技术是多么稀缺、昂贵和宝贵。
定位线索：题干“The example of early 17th-century Virginians”→答案句“early 17th-century Virginians would sometimes bum down their homes”；例子前的观点句“Later civilisations would value the skilled blacksmith's labour in a nail even more than the raw material”和例子后的观点句“The idea that one might bum down an entire house just to reclaim the nails underlines how scarce, costly and valuable the simple-seeming technology was”；文中“scarce, costly and valuable”对应选项D“preciousness”。
解析：例证题的关键是例子前后的观点句。例子本身是弗吉尼亚人烧房取钉，但答案依据是例子后的观点句“The idea that one might bum down an entire house just to reclaim the nails underlines how scarce, costly and valuable the simple-seeming technology was”，即说明钉子技术在当时很珍贵。选项D“show the preciousness of nail-making technology at that time”正是对该观点句的同义转述。选项A“highlight the thriftiness of early American colonists”偷换概念，例子虽体现节俭但重点在钉子价值；选项B“illustrate the high status of blacksmiths”无中生有，文中未提铁匠地位；选项C“contrast the attitudes of different civilisations”范围扩大，例子仅说明后来的文明，未对比。
23. What played the major role in lowering the price of nails after the late 1700s?
- A. Increased productivity.
- B. Wider use of new energies.
- C. Fiercer market competition.
- D. Reduced cost of raw materials.
答案：A
答案句：The price of nails fell by 90% between the late 1700s and mid-1900s, as economist Daniel Sichel points out in a research paper. According to Sichel, although the falling price of nails was driven partly by cheaper iron and cheaper energy, most of the credit goes to nail manufacturers who simply found more efficient ways to turn steel into nails.
参考译文：正如经济学家Daniel Sichel在一篇研究论文中指出的，从18世纪末到20世纪中期，钉子价格下降了90%。根据Sichel的说法，尽管钉子价格下降部分是由更便宜的铁和更便宜的能源推动的，但大部分功劳归于钉子制造商，他们找到了更有效的方法将钢转化为钉子。
定位线索：题干“What played the major role in lowering the price of nails after the late 1700s”→答案句“most of the credit goes to nail manufacturers who simply found more efficient ways to turn steel into nails”；文中“found more efficient ways”对应选项A“Increased productivity”。
解析：题干问降低钉子价格的主要因素，答案句明确指出“most of the credit goes to nail manufacturers who simply found more efficient ways to turn steel into nails”，即制造商提高生产效率是主因。选项A“Increased productivity”是对“found more efficient ways”的同义转述。选项D“Reduced cost of raw materials”偷换概念，文中虽提到“cheaper iron”但明确说“partly”，非主要因素；选项B“Wider use of new energies”偷换概念，文中“cheaper energy”非新能源；选项C“Fiercer market competition”无中生有，文中未提竞争。
24. It can be learned from Paragraph 5 that nails ____
- A. have undergone many technological improvements.
- B. have remained basically the same since Roman times.
- C. are less studied than other everyday products.
- D. are one of the world’s most significant inventions.
答案：B
答案句：Nails themselves have changed over the years, but Sichel studied them because they haven't changed much. Roman lamps and Roman chariots are very different from LED strips and sports cars, but Roman nails are still clearly nails.
参考译文：钉子本身多年来有所变化，但Sichel研究它们是因为它们变化不大。罗马的灯和罗马的战车与LED灯条和跑车非常不同，但罗马的钉子仍然是明显的钉子。
定位线索：题干“It can be learned from Paragraph 5”→答案句取自第5段“Nails themselves have changed over the years, but Sichel studied them because they haven't changed much”和“Roman nails are still clearly nails”；文中“haven't changed much”和“still clearly nails”对应选项B“have remained basically the same since Roman times”。
解析：题干问从第5段能推断出什么，答案句指出钉子“haven't changed much”且“Roman nails are still clearly nails”，说明钉子自罗马时代以来基本没变。选项B“have remained basically the same since Roman times”是对此的合理推断。选项A“have undergone many technological improvements”与原文矛盾，原文说“haven't changed much”；选项C“are less studied than other everyday products”无中生有，文中未比较研究程度；选项D“are one of the world's most significant inventions”无中生有，文中未提重要性。
25. Which of the following best summarises the last two paragraphs?
- A. Cheap technologies bring about revolutionary change.
- B. Technological innovation is integral to economic success.
- C. Technology defines people’s understanding of the world.
- D. Sophisticated technologies develop from small inventions.
答案：A
答案句：I make no apology for being obsessed by a particular feature of these objects: their price. I am an economist, after all. After writing two books about the history of inventions, one thing I've learnt is that while it is the enchantingly sophisticated technologies that get all the hype, it's the cheap technologies that change the world. The Gutenberg printing press transformed civilisation not by changing the nature of writing but by changing its cost—and it would have achieved little without a parallel collapse in the price of surfaces to write on, thanks to an often-overlooked technology called paper. Solar panels had few niche uses until they became cheap; now they are transforming the global energy system.
参考译文：我不为自己痴迷于这些物品的一个特定特征而道歉：它们的价格。毕竟我是经济学家。在写了两本关于发明史的书之后，我学到的一件事是，虽然令人着迷的复杂技术得到了所有炒作，但改变世界的是廉价技术。古腾堡印刷机改变文明不是通过改变写作的本质，而是通过改变其成本——如果没有一种经常被忽视的叫做纸的技术使书写表面价格同步暴跌，它几乎不会取得什么成就。太阳能电池板在变得便宜之前只有很少的利基用途；现在它们正在改变全球能源系统。
定位线索：题干“best summarises the last two paragraphs”→末两段主题句“it's the cheap technologies that change the world”；文中“cheap technologies”对应选项A“Cheap technologies”，“change the world”对应“bring about revolutionary change”。
解析：题干问最后两段的最佳概括，第6段主题句“it's the cheap technologies that change the world”直接点明主旨，第7段用印刷机和太阳能电池板两个例子支撑这一观点。选项A“Cheap technologies bring about revolutionary change”是对“cheap technologies that change the world”的同义转述。选项B“Technological innovation is integral to economic success”偷换概念，文中未提经济成功；选项C“Technology defines people's understanding of the world”无中生有，文中未提理解世界；选项D“Sophisticated technologies develop from small inventions”偷换概念，文中强调廉价技术而非复杂技术。