In the past, falling oil prices have given a boost to the world economy, but recent forecasts for global growth have been toned down, even as oil prices sink lower and lower. Does that mean the link b

are that great. But I can tell you that I like this guy. Thats because he plans to ban tipping in favor of paying his servers an actual living wage.

I hate tipping.

I hate it because it’s an obligation disguised as an option. I hate it for the post-dinner math it requires of me. But mostly, I hate tipping because I believe I would be in a better place if pay decisions regarding employees were simply left up to their employers, as is the custom in virtually every other industry.

Most of you probably think that you hate tipping, too. Research suggests otherwise. You actually love tipping! You like to feel that you have a voice in how much money your server makes. No matter how the math works out, you persistently view restaurants with voluntary tipping systems as being a better value, which makes it extremely difficult for restaurants and bars to do away with the tipping system.

One argument that you tend to hear a lot from the pro-tipping crowd seems logical enough: the service is better when waiters depend on tips, presumably because they see a benefit to successfully veiling their contempt for you. Well, if this were true we would all be slipping a few 100-dollar bill to our doctors on the way out their doors, too. But as it turns out, waiters see only a tiny bump in tips when they do an exceptional job compared to a passable one. Waiters, keen observers of humanity that they are , are catching on to this; in one poll, a full 30% said they didnt believe the job they did had any impact on the tips they received.

So come on, folks: get on board with ditching the outdated tip system. Pay a little more upfront for your beer or burger. Support Bill Perrys pub, and any other bar or restaurant that doesnt ask you to do drunken math.

46. What can we learn about Bill Perry from the passage?

A) He runs a pub that serves excellent beer.

B) He intends to get rid of the tipping practice.

C) He gives his staff a considerable sum for tips.

D) He lives comfortably without getting any tips.

47. What is the main reason why the author hates tipping?

A) It sets a bad example for other industries.

B) It adds to the burden of ordinary customers.

C) It forces the customer to compensate the waiter.

D) It poses a great challenge for customers to do math.

48. Why do many people love tipping according to the author?

A) They help improve the quality of the restaurants they dine in.

B) They believe waiters deserve such rewards for good service.

C) They want to preserve a wonderful tradition of the industry.

D) They can have some say in how much their servers earn.

49. What have some waiters come to realize according to a survey?

A) Service quality has little effect on tip size.

B) It is in human nature to try to save on tips.

C) Tips make it more difficult to please customers.

D) Tips benefit the boss rather than the employees.

50. What does the author argue for in the passage?

A) Restaurants should calculate the tips for customers.

B) Customers should pay more tips to help improve service.

C) Waiters deserve better than just relying on tips for a living.

D) Waiters should be paid by employers instead of customers.

e believe make us special. This is a grand challenge for our age and it may require an "irrational" response.

One of the most significant pieces of news from the US in early 2017 was the efforts of Google to make autonomous driving a reality. According to a report, Google's self-driving cars clocked 1,023,330 km, and required human intervention 124 times. That is one intervention about every 8,047 km of autonomous driving. But even more impressive is the progress in just a single year: human interventions fell from 0.8 times per thousand miles to 0.2, a 400% improvement. With such progress, Google's cars will easily surpass my own driving ability later this year.

Driving once seemed to be a very human skill. But we said that about chess, too. Then a computer beat the human world champion, repeatedly. The board game Go(围棋)took over from chess as a new test for human thinking in 2016, when a computer beat one of the world's leading professional Go players. With computers conquering what used to be deeply human tasks, what will it mean in the future to be human? I worry about my six-year-old son. What will his place bе in a world where machines beat us in one area after another? He'll never calculate faster, never drive better, or even fly more safely. Actually, it all comes down to a fairly simple question： What's so special about us? It can't be skills like arithmetic, which machines already excel in. So far, machines have a pretty hard time emulating creativity, arbitrary enough not to be predicted by a computer, and yet more than simple randomness.

Perhaps, if we continue to improve information-processing machines, well soon have helpful rational assistants. So we must aim to complement the rationality of the machine, rather than to compete with it. If I'm right, we should foster a creative spirit because a dose of illogical creativity will complement the rationality of the machine. Unfortunately, however, our education system has not caught up to the approaching reality. Indeed, our schools and universities are structured to mould pupils to be mostly obedient servants of rationality, and to develop outdated skills in interacting with outdated machines. We need to help our children learn how to best work with smart computers to improve human decision-making. But most of all we need to keep the long-term perspective in mind: that even if computers will outsmart us, we can still be the most creative. Because if we aren't, we won't be providing much value in future ecosystems，and that may put in question the foundation for our existence.

51. What is the author's greatest concern about the use of AI?

A) Computers are performing lots of creative tasks.

B) Many abilities will cease to be unique to human beings.

C) Computers may become more rational than humans.

D) Many human skills are fast becoming outdated.

52. What impresses the author most in the field of AI?

A) Google's experimental driverless cars require little human intervention.

B) Google's cars have surpassed his driving ability in just a single year.

C) Google has made huge progress in autonomous driving in a short time.

D) Google has become a world leader in the field of autonomous driving.

53. What do we learn from the passage about creativity?

A) It is rational.

B) It is predictable.

C) It is human specific.

D) It is yet to be emulated by AI.

54. What should schools help children do in the era of AI?

A) Cultivate original thinking.

B) Learn to work independently.

C) Compete with smart machines.

D) Understand how AI works.

55. How can we humans justify our future existence?

A) By constantly outsmarting computers.

B) By adopting a long-term perspective.

C) By rationally compromising with AI.

D) By providing value with our creativity.

When I re-entered the full-time workforce a few years ago after a decade of solitary self-employment, there was one thing I was looking forward to the most: the opportunity to have work friends once again. It wasn't until I entered the corporate world that I realized, for me at least, being friends with colleagues didn't emerge as a priority at all. This is surprising when you consider the prevailing emphasis by scholars and trainers and managers on the importance of cultivating close interpersonal relationships at work. So much research has explored the way in which collegial (同事的)ties can help overcome a range of workplace issues affecting productivity and the quality of work output such as team-based conflict, jealousy, undermining, anger, and more.

Perhaps my expectations of lunches, water-cooler gossip and caring, deep-and-meaningful conversations were a legacy of the last time I was in that kind of office environment. Whereas now, as I near the end of my fourth decade, I realize work can be fully functional and entirely fulfilling without needing to be best mates with the people sitting next to you.

In an academic analysis just published in the profoundly-respected Journal of Management, researchers have looked at the concept of "indifferent relationships". It's a simple term that encapsulates (概括) the fact that relationships at work can reasonably be non-intimate, inconsequential, unimportant and even, dare I say it, disposable or substitutable.

Indifferent relationships are neither positive nor negative. The limited research conducted thus far indicates they're especially dominant among those who value independence over cooperation, and harmony over confrontation. Indifference is also the preferred option among those who are socially lazy. Maintaining relationships over the long term takes effort. For some of us, too much effort .

As noted above, indifferent relationships may not always be the most helpful approach in resolving some of the issues that pop up at work. But there are nonetheless several empirically proven benefits. One of those is efficiency. Less time chatting and socializing means more time working and(产出).

The other is self-esteem. As human beings, we're primed to compare ourselves to each other in what is an anxiety-inducing phenomenon. Apparently, we look down on acquaintances more so than Mends. Since the former is most common among those inclined towards indifferent relationships, their predominance can bolster individuals' sense of self-worth.

Ego aside, a third advantage is that the emotional neutrality of indifferent relationships has been found to enhance critical evaluation, to strengthen one's focus on task resolution, and to gain greater access to valuable information. None of that might be as fun as after-work socializing but, hey, I'll take it anyway.

46. What did the author realize when he re-entered the corporate world?

A) Making new Mends with his workmates was not as easy as he had anticipated.

B) Cultivating positive interpersonal relationships helped him expel solitary feelings.

C) Working in the corporate world requires more interpersonal skills than self-employment.

D) Building close relationships with his colleagues was not as important as he had ejected.

47. What do we learn from many studies about collegial relationships?

A) Inharmonious relationships have an adverse effect on productivity.

B) Harmonious relationships are what many companies aim to cultivate.

C) Close collegial relationships contribute very little to product quality.

D) Conflicting relationships in the workplace exist almost everywhere.

48. What can be inferred about relationships at work from an academic analysis?

A) They should be cultivated.

B) They are virtually irrelevant.

C) They are vital to corporate culture.

D) They should be reasonably intimate.

49. What does the author say about people who are socially lazy?

A) They feel uncomfortable when engaging in social interactions.

B) They often find themselves in confrontation with their colleagues.

C) They are unwilling to make efforts to maintain workplace relationships.

D) They lack basic communication skills in dealing with interpersonal issues.

60. What is one of the benefits of indifferent relationships?

A) They provide fun at work.

B) They help control emotions.

C) They help resolve differences.

D) They improve work efficiency.

The future of personal satellite technology is here—are we ready for it?

A)Satellites used to be the exclusive playthings of rich governments and wealthy corporations. But increasingly, as space becomes more democratized, they are coming within reach of ordinary people. Just like drones (无人机)before them, miniature satellites are beginning to fundamentally transform. our conceptions of who gets to do what up above our heads.

B)As a recent report from the National Academy of Sciences highlights, these satellites hold tremendous potential for making satellite-based science more accessible than ever before. However, as the cost of getting your own satellite in orbit drops sharply, the risks of irresponsible use grow. The question here is no longer "Can we?" but "Should we?" What are the potential downsides of having a slice of space densely populated by equipment built by people not traditionally labeled as "professionals" ? And what would the responsible and beneficial development and use of this technology actually look like? Some of the answers may come from a nonprofit organization that has been building and launching amateur satellites for nearly 50 years.

C)Having your personal satellite launched into orbit might sound like an idea straight out of science fiction. But over the past few decades a unique class of satellites has been created that fits the bill: CubeSats. The "Cube" here simply refers to the satellite's shape. The most common CubeSat is a 10cm cube, so small that a single CubeSat could easily be mistaken for a paperweight on your desk. These mini-satellites can fit in a launch vehicle's formerly "wasted space. " Multiples can be deployed in combination for more complex missions than could be achieved by one CubeSat alone.

D)Within their compact bodies these minute satellites are able to house sensors and communications receivers/transmitters that enable operators to study Earth from space, as well as space around Earth. They're primarily designed for Low Earth Orbit (LEO)—an easily accessible region of space from around 200 to 800 miles above Earth, where human-tended missions like the Hubble Space Telescope and the International Space Station (ISS) hang out. But they can attain more distant orbits; NASA plans for most of its future Earth-escaping payloads (to the moon and Mars especially) to carry CubeSats.

E)Because they're so small and light, it costs much less to get a CubSat into Earth's orbit than a traditional communications or GPS satellite. For instance,a research group here at Arizona State University recently claimed their developmental small CubeSats could cost as little as $3,000 to put in orbit. This decrease in cost allows researchers, hobbyists and even elementary school groups to put simple instruments into LEO or even having them deployed from the ISS.

F)The first CubeSat was created in the early 2000s,as a way of enabling Stanford graduate students to design, build, test and operate a spacecraft with similar capabilities to the USSR's Sputnik (前苏联的人造卫星).Since then, NASA, the National Reconnaissance Office and even Boeing have all launched and operated CubeSats. There are more than 130 currently in operation. The NASA Educational Launch of Nano Satellite program, which offers free launches for educational groups and science missions, is now open to U. S. nonprofit corporations as well. Clearly, satellites are not just for rocket scientists anymore.

G)The National Academy of Sciences report emphasizes CubeSats' importance in scientific discovery and the training of future space scientists and engineers. Yet it also acknowledges that widespread deployment of LEO CubeSats isn't risk-free. The greatest concern the authors raise is space debris—pieces of "junk" that orbit the earth, with the potential to cause serious damage if they collide with operational units, including the ISS.

H)Currently, there aren't many CubeSats and they're tracked closely. Yet as LEO opens up to more amateur satellites, they may pose an increasing threat. As the report authors point out, even near-misses might lead to the "creation of a burdensome regulatory framework and affect the future disposition of science CubeSats."

I)CubeSat researchers suggest that now's the time to ponder unexpected and unintended possible consequences of more people than ever having access to their own small slice of space. In an era when you can simply buy a CubeSat kit off the shelf, how can we trust the satellites over our heads were developed with good intentions by people who knew what they were doing? Some "expert amateurs" in the satellite game could provide some inspiration for how to proceed responsibly.

J)In 1969.the Radio Amateur Satellite Corporation (AMSAT) was created in order to foster ham radio enthusiasts' (业余无线电爱好者)participation in space research and communication. It continued the efforts, begun in 1961, by Project OSCAR—a U. S. -based group that built and launched the very first nongovernmental satellite just four years after Sputnik. As an organization of volunteers, AMSAT was putting "amateur" satellites in orbit decades before the current CubeSat craze. And over time, its members have learned a thing or two about responsibility. Here, open-source development has been a central principle. Within the organization, AMSAT has a philosophy of open sourcing everything—making technical data on all aspects of their satellites fully available to everyone in the organization, and when possible, the public. According to a member of the team responsible for FOX 1-A, AMSAT's first CubeSat, this means that there's no way to sneak something like explosives or an energy emitter into an amateur satellite when everyone has access to the designs and implementation.

K)However, they're more cautious about sharing information with nonmembers, as the organization guards against others developing the ability to hijack and take control of their satellites. This form. of "self-governance" is possible within long-standing amateur organizations that, over time, are able to build a sense of responsibility to community members,as well as society in general. But what happens when new players emerge, who don't have deep roots within the existing culture?

L)Hobbyists and students are gaining access to technologies without being part of a long-standing amateur establishment. They're still constrained by fimders, launch providers and a series of regulations—all of which rein in what CubeSat developers can and cannot do. But there's a danger they're ill-equipped to think through potential unintended consequences. What these unintended consequences might be is admittedly far from clear. Yet we know innovators can be remarkably creative with taking technologies in unexpected directions. Think of something as seemingly benign as the cellphone—we have microfinance and text-based social networking at one end of the spectrum, and improvised (临时制作的)explosive devices at the other.

M)This is where a culture of social responsibility around CubeSats becomes important-not simply to ensure that physical risks are minimized, but to engage with a much larger community in anticipating and managing less obvious consequences of the technology. This is not an easy task. Yet the evidence from AMSAT and other areas of technology development suggests that responsible amateur communities can and do emerge around novel technologies. The challenge here, of course, is ensuring that what an amateur community considers to be responsible, actually is. Here's where there needs to be a much wider public conversation that extends beyond government agencies and scientific communities to include students, hobbyists，and anyone who may potentially stand to be affected by the use of CubeSat technology.

36. Given the easier accessibility to space, it is time to think about how to prevent misuse of satellites.

37. A group of mini-satellites can work together to accomplish more complex tasks.

38. The greater accessibility of mini-satellites increases the risks of their irresponsible use.

39. Even school pupils can have their CubeSats put in orbit owing to the lowered launching cost.

40. is careful about sharing information with outsiders to prevent hijacking of their satellites.

41. NASA offers to launch CubeSats free of charge for educational and research purposes.

42. Even with constraints, it is possible for some creative developers to take the CubeSat technology in directions that result in harmful outcomes.

43. While making significant contributions to space science, CubeSats may pose hazards to other space vehicles.

44. Mini-satellites enable operators to study Earth from LEO and space around it.

45. AMSAT operates on the principle of having all its technical data accessible to its members, preventing the abuse of amateur satellites.

__ become brittle (脆的)at temperatures below about -25℃ unless they are mixed with other metals. Now, though, a novel type of steel has been developed that resists __27__ at much lower temperatures, while retaining its strength and toughness—without the need for expensive __28__.

Steel's fragility at low temperatures first became a major concern during the Second World War. After German U-boats torpedoed (用鱼雷攻击)numerous British ships, a 2,700-strong fleet of cheap- and-cheerful "Liberty ships" was introduced to replace the lost vessels, providing a lifeline for the __29__ British. But the steel shells of hundreds of the ships __30__ in the icy north Atlantic, and 12 broke in half and sank.

Brittleness remains a problem when building steel structures in cold conditions, such as oil rigs in the Arctic. So scientists have __31__ to find a solution by mixing it with expensive metals such as nickel.

Yuuji Kimura and colleagues in Japan tried a more physical __32__. Rather than adding other metals, they developed a complex mechanical process involving repeated heating and very severe mechanical deformation, known as tempforming.

The resulting steel appears to achieve a combination of strength and toughness that is __33__ to that of modem steels that are very rich in alloy content and, therefore, very expensive.

Kimura's team intends to use its tempformed steel to make ultra-high strength parts, such as bolts. They hope to reduce both the number of __34__ needed in a construction job and their weight—by replacing solid supports with __35__ tubes, for example. This could reduce the amount of steel needed to make everything from automobiles to buildings and bridges.

A)abruptly

B)additives

C)approach

D)ardently

E)besieged

F)channel

G)comparable

H)components

I)cracked

J)fractures

K)hollow

L)relevant

M)reshuffled

N)strived

O)violent