Section C: Reading Comprehension
Directions: There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A), B), C) and D). You should decide on the best choice and mark the corresponding letter on Answer Sheet 2 with a single line through the centre.
Passage One
Questions 46 to 50 are based on the following passage.
How can one person enjoy good health, while another person looks old before her time? Humans have been asking this question for thousands of years, and recently, it’s becoming clearer and clearer to scientists that the differences between people’s rates of aging lie in the complex interactions among genes, social relationships, environments and lifestyles. Even though you were born with a particular set of genes, the way you live can influence how they express themselves. Some lifestyle factors may even turn genes on or shut them off.
Deep within the genetic heart of all our cells are telomeres, or repeating segments of noncoding DNA (染色体) that live at the ends of the chromosomes. They form caps at the ends of the chromosomes and keep the genetic material together. Shortening with each cell division, they help determine how fast a cell ages. When they become too short, the cell stops dividing altogether. This isn’t the only reason a cell can age—there are other stresses on cells we don’t yet understand very well—but short telomeres are one of the major reasons human cells grow old. We’ve devoted most of our careers to studying telomeres, and one extraordinary discovery from our labs is that telomeres can actually lengthen.
Scientists have learned that several thought patterns appear to be unhealthy for telomeres, and one of them is cynical hostility. Cynical hostility is defined by high anger and frequent thoughts that other people cannot be trusted. Someone with hostility doesn’t just think, “I hate to stand in long lines”; they think, “Others deliberately speed up and beat me to my rightful position in the line!”—and then get violently agitated. People who score high on measures of cynical hostility tend to get more heart disease, metabolic disease and often die at younger ages. They also have shorter telomeres. In a study of British civil servants, men who scored high on measures of cynical hostility had shorter telomeres than men whose hostility scores were low. The most hostile men were 30% more likely to have short telomeres.
What this means: aging is a dynamic process that could possibly be accelerated or slowed—and, in some aspects, even reversed. To an extent, it has surprised us and the rest of the scientific community that telomeres do not simply carry out the commands issued by your genetic code. Your telomeres are listening to you. The foods you eat, your response to challenges, the amount of exercise you get, and many other factors appear to influence your telomeres and can prevent premature aging at the cellular level. One of the keys to enjoying good health is simply doing your part to foster healthy cell renewal.
46. What have scientists come to know better today?
47. Why are some lifestyle factors considered extremely important?
48. What have the author and his colleagues discovered about telomeres?
49. What have scientists learned about cynical hostility?
50. What do we learn from the last paragraph about the process of aging?
Passage Two
Questions 51 to 55 are based on the following passage.
Scientists have created by accident an enzyme (酶) that breaks down plastic drinks bottles. The breakthrough could help solve the global plastic pollution crisis by enabling for the first time the full recycling of bottles.
The new research was spurred by the discovery in 2016 of the first bacterium that had naturally evolved to eat plastic at a waste dump in Japan. Scientists have now revealed the detailed structure of the crucial enzyme produced by the bug.
An international team then adjusted the enzyme to see how it had evolved, but tests showed they had accidentally made the molecule even better at breaking down the plastic used for drinks bottles. “What actually turned out was we improved the enzyme, which was a bit of a shock,” said head researcher Prof. McGeehan, at the University of Portsmouth, UK.
Currently, the enzyme takes a few days to start breaking down the plastic, far faster than the centuries it takes in the oceans, but the researchers are optimistic this can be speeded up even further and become a viable large-scale process.
“What we are hoping to do is use this enzyme to turn this plastic back into its original components, so we can literally recycle it back to plastic,” said McGeehan. “It means we won’t need to dig up any more oil and, fundamentally, it should reduce the amount of plastic in the environment.”
About 1 million plastic bottles are sold each minute around the globe and, with just 14% recycled, many end up in the oceans where they have polluted even the remotest parts, harming marine life and potentially people who eat sea food. “Plastic is incredibly resistant to degradation,” said McGeehan. “It is one of these wonder materials that has been made a little bit too well.”
Currently those bottles that are recycled can only be turned into opaque fibres for clothing or carpets, while the new enzyme indicates a way to recycle old clear plastic bottles back into new clear plastic bottle.
“You are always up against the fact that oil is cheap, so plastic is cheap,” said McGeehan. “It is so easy for manufacturers to generate more of that stuff, rather than even try to recycle, but I believe there is a public interest here: perception is changing so much that companies are starting to look at how they can properly recycle these bottles.”
Prof. Adisa Azapagic, at the University of Manchester in the UK, agreed the enzyme could be useful but added: “A full life-cycle assessment would be needed to ensure that the technology does not solve one environmental problem—waste—at the expense of others, including additional greenhouse gas emissions.”
51. What do we learn from the passage about an enzyme scientists have created?
52. What does the passage say about the bug that produces the important enzyme?
53. By adjusting the enzyme produced by the bug, the scientists ____________.
54. What does Prof. McGeehan say about the recycling of plastic bottles?
55. What is Prof. Adisa Azapagic’s advice concerning the application of the enzyme?
Answers & Explanations (答案与解析)
Passage One
46. A。解析：题干问“科学家如今更清楚地了解了什么”。第一段指出：“...it’s becoming clearer and clearer to scientists that the differences between people’s rates of aging lie in the complex interactions among genes, social relationships, environments and lifestyles.”（对科学家来说越来越清楚的是，人们衰老速度的差异在于基因、社会关系、环境和生活方式之间复杂的相互作用）。这意味着他们更了解衰老速度不同的原因，对应选项 A（Why people age at different rates 为什么人们以不同的速度衰老）。
47. B。解析：题干问“为什么一些生活方式因素被认为极其重要”。第一段最后一句指出：“Some lifestyle factors may even turn genes on or shut them off.”（一些生活方式因素甚至可能开启或关闭基因）。这说明生活方式决定了基因如何发挥作用，对应选项 B（They may determine how genes function 它们可能决定基因如何发挥作用）。
48. C。解析：题干问“作者和他的同事对端粒有什么发现”。第二段最后一句指出：“We’ve devoted most of our careers to studying telomeres, and one extraordinary discovery from our labs is that telomeres can actually lengthen.”（我们的大部分职业生涯都致力于研究端粒，而我们实验室的一个非凡发现是端粒实际上可以变长）。端粒可以变长意味着其变短的过程可以被逆转，对应选项 C（Their shortening process can be reversed 它们变短的过程可以被逆转）。
49. B。解析：题干问“科学家对愤世嫉俗的敌意了解了什么”。第三段首句指出：“Scientists have learned that several thought patterns appear to be unhealthy for telomeres, and one of them is cynical hostility.”（科学家了解到，有几种思维模式似乎对端粒不健康，其中之一就是愤世嫉俗的敌意）。unhealthy for telomeres 即对端粒有不利影响，对应选项 B（It may produce an adverse effect on telomeres 它可能会对端粒产生不利影响）。
50. D。解析：题干问“从最后一段我们了解到衰老过程是怎样的”。最后一段首句指出：“What this means: aging is a dynamic process that could possibly be accelerated or slowed—and, in some aspects, even reversed.”（这意味着：衰老是一个动态过程，可能会加速或减缓——在某些方面甚至可能逆转）。随后说明通过生活方式（饮食、运动等）可以影响衰老。这说明衰老在某种程度上是可以控制的，对应选项 D（It may be controlled to a degree 它可以在某种程度上被控制）。
Passage Two
51. B。解析：题干问“从文章中我们了解到科学家创造的酶的什么信息”。第一段指出：“Scientists have created by accident an enzyme that breaks down plastic drinks bottles. The breakthrough could help solve the global plastic pollution crisis by enabling for the first time the full recycling of bottles.”（科学家偶然创造了一种分解塑料饮料瓶的酶。这一突破可能有助于通过首次实现瓶子的全面回收来解决全球塑料污染危机）。对应选项 B（It may make full recycling of plastic bottles a reality 它可能使塑料瓶的全面回收成为现实）。A选项中“during a lab experiment accident”表述错误，原文是 by accident（偶然地/意外地）创造了酶，并非发生了实验事故。
52. A。解析：题干问“关于产生这种重要酶的虫子（细菌），文章说了什么”。第二段首句指出：“The new research was spurred by the discovery in 2016 of the first bacterium that had naturally evolved to eat plastic at a waste dump in Japan.”（这项新研究受到2016年一项发现的启发，该发现是在日本的一个垃圾场首次发现了自然进化出吃塑料能力的细菌）。eat plastic 对应 consume plastics，对应选项 A（It has a natural ability to consume plastics 它有消耗塑料的天生能力）。
53. A。解析：题干问“通过调整这种虫子产生的酶，科学家们____”。第三段首句指出：“An international team then adjusted the enzyme... but tests showed they had accidentally made the molecule even better at breaking down the plastic...”（一个国际团队随后调整了这种酶……但测试显示，他们偶然地使这种分子在分解塑料方面变得更好）。made... even better 对应 made it more effective，accidentally 对应 by chance。因此选 A（偶然地使它变得更有效）。
54. D。解析：题干问“McGeehan 教授关于塑料瓶回收说了什么”。第八段引用他的话说：“...perception is changing so much that companies are starting to look at how they can properly recycle these bottles.”（……观念正在发生如此大的变化，以至于公司开始着眼于如何正确回收这些瓶子）。companies starting to look at how 对应选项 D（Manufacturers are beginning to explore ways of doing it 制造商开始探索这样做的方法）。
55. C。解析：题干问“Adisa Azapagic 教授对这种酶的应用有何建议”。最后一段引用她的话说：“A full life-cycle assessment would be needed to ensure that the technology does not solve one environmental problem—waste—at the expense of others, including additional greenhouse gas emissions.”（需要进行全面的生命周期评估，以确保该技术不会以其他环境问题（包括额外的温室气体排放）为代价来解决一个环境问题（废物））。这说明她建议评估其可能的负面影响，对应选项 C（Assessing its possible negative impact on the environment 评估它对环境可能的负面影响）。
核心搭配与高分句型
【核心搭配与高频短语】
lie in：在于，取决于（differences... lie in the complex interactions）
turn on / shut off：开启 / 关闭（turn genes on or shut them off）
carry out：执行，贯彻（carry out the commands）
break down：分解，瓦解（breaks down plastic drinks bottles）
by accident：偶然地，意外地（created by accident an enzyme）
up against：面临，遭遇困难（You are always up against the fact that...）
at the expense of：以...为代价，牺牲（at the expense of others）
【亮点句型解析】
It is/was + 形容词 + to sb + that 句型：
"...it’s becoming clearer and clearer to scientists that the differences... lie in the complex interactions..."
（对于科学家来说越来越清楚的是，差异……在于复杂的相互作用……）使用 `it` 作形式主语，使得长达数十词的真正主语（that从句）后置，避免了头重脚轻，句式极其平稳。
"...it’s becoming clearer and clearer to scientists that the differences... lie in the complex interactions..."
（对于科学家来说越来越清楚的是，差异……在于复杂的相互作用……）使用 `it` 作形式主语，使得长达数十词的真正主语（that从句）后置，避免了头重脚轻，句式极其平稳。
So... that... 结果状语从句：
"...perception is changing so much that companies are starting to look at how they can properly recycle these bottles."
（……观念正在发生如此大的变化，以至于公司开始着眼于如何正确回收这些瓶子。）生动强调了公众观念转变之大，已经直接推动了企业的实际行动。
"...perception is changing so much that companies are starting to look at how they can properly recycle these bottles."
（……观念正在发生如此大的变化，以至于公司开始着眼于如何正确回收这些瓶子。）生动强调了公众观念转变之大，已经直接推动了企业的实际行动。