We’ve all been there. You’re around new people and you just want to impress them. It can be easy to pretend you know about movies, politics, or science just to get through an awkward situation. But contrary to what feels most natural, a new series of five studies from Pepperdine University shows that those who can admit when they don’t know something tend to actually have more knowledge. If you want to make those people think you’re smart, maybe the best thing to say is “I don’t know.”

For the study, which was led by Elizabeth Krumrei-Mancuso, the team of researchers had one question: Is there a knowledge benefit to admitting intellectual fallibility? To find out, they ran not one, not two, but five separate experiments. They engaged nearly 1,200 participants in their study, and evaluated them using a number of questionnaires testing their cognitive abilities, measuring their own predictions of their cognitive abilities, and, of course, rating their levels of intellectual humility.

For that last part, they used different methods in different studies to get a more well﹣rounded set of results. One IH survey used eight questions to assess participants on two elements: the “Knowing﹣It﹣All” subscale, which judged their attitudes of intellectual superiority, and the “Intellectual Openness” subscale, which assessed how open they were to learning from others. In other studies, they used the 22-question “Comprehensive Intellectual Humility Scale,” which assesses participants on four elements: independence of intellect and ego, openness to revising one’s viewpoint, respect for others’ viewpoints, and lack of intellectual overconfidence. The five studies were used to examine past learning, thinking styles, traits, and motivations.

What the researchers may agree is that the best thing to remember is that curiosity seems to be a good thing. The world is big, and it’s impossible to know everything. At your next dinner party, ask questions and admit your own cluelessness. It might make you a little less clueless next time.

38．Why did Elizabeth Krumrei-Mancuso led the study？    

A．to find out whether admitting that you don’t know something is beneficial.

B．to find the certain benefit of admitting intellectual disability.

C．to compare the modest people with proud people.

D．to stress the importance of curiosity.

39．From the article, we can learn that     .

A．we all tend to pretend we have a good command of knowledge.

B．the study engaged over 1,200 participants in their study.

C．”I don’t know” may be a good answer to people who ask you if you are clever.

D．a number of questionnaires are used to test participants’ cognitive humility.

40．What is the best title of the article？    

A．Be yourself!                                              B．Admitting your fallibility!

C．Express your drawbacks!                            D．Let curiosity lead you!

  A native of Florida, U. S. , Hannah Herbst, 17, uses water power to deal with energy poverty. Herbst has risen to fame with the development of BEACON, an ocean energy probe that seeks to offer a stable power source to developing countries by using untapped energy from ocean currents.

She told Teen Vogue , " I was really involved in theater and athletics and I'm still really into those things. When I was in the seventh grade, I was put into a summer camp. The minute I got there I realized that I was the only girl in the program. I wanted to quit at that moment. But my dad told me, ' Just try it. '  I tried it for that day and it changed my life. ”

“At the camp, we started building the robots, which is something I had never done before but many of the boys had, and I realized it was a platform for problem-solving. We were solving simple tasks like how to push a robot off a platform. Learning from my partners as well as online articles about how to program and build was really interesting to me," said Herbst.

Later that year, she received a letter from her pen pal, Ruth, who lives in Ethiopia, and learned that she was living in energy poverty with minimal access to electricity and medical supplies. " I knew that I wanted to do something to help, so I created BEACON, she said.

The device is made from 90% recycled materials easily found throughout the world, including 2-liter bottles and recycled spoons. It costs $ 12 to make and can produce enough electricity to power an LED light. Hannah imagines BEACON being used in developing countries to power pumps for fresh water and she is working on polishing it to get it available to people all over the world.

4．What advice does Herbst most likely give to teens by her camp experience?

A．Quilting to gain more.

B．Giving something a go.

C．Developing various interests.

D．Avoiding favorable conditions

5．What kind of summer camp did Herbst join in the seventh grade?

A．Athletic.                                                   B．Literature.

C．Theater.                                                    D．Engineering.

6．Which words can best describe Hannah Herbst?

A．Energetic and kind.                                    B．Helpful and creative.

C．Generous and modest.                                D．Careful and adventurous.

7．What can we know about BEACON?

A．It is a powerful LED light.

B．It's made without any cost.

C．Its materials are accessible.

D．It has been put on the market.

  Chinese social media apps have struggled to win over users beyond their home. TikTok is changing that. In the space of just two years, the app has attracted more than half a billion users — around 40% of them outside China --who share short videos of themselves singing, cooking, dancing or just being silly.

Created by the Beijing-based Internet technology company Byte Dance, TikTok has gained an international edge over China's influential social media platforms, such as Tencent's WeChat, Sina Weibo (WB) and Youku of Alibaba (BABA).

What makes Byte Dance better is its right direction and achievement in the social media category, which is largely controlled by Facebook ( FB) , Twitter and Snap 一 all Western companies, said Randy Nelson _, head of Mobile Insights at analytics firm Sensor Tower. Social video apps reached new levels of popularity this year. Three of them are in the top 10 most downloaded apps worldwide, according to Sensor Tower. Byte Dance owns two of the three: Vigo Video and TikTok. The other is Instagram, which belongs to Facebook.

Byte Dance calls itself an artificial intelligence company. It uses machine learning   and algorithms to figure out what people like and give them more of what they want to see. the company is best known in China for the popular news app Toutiao, which was put into use in 2012. People got hooked on the app' s customized news feeds quickly. Toutiao now has more than 240 million monthly active users that spend on average 74 minutes per day on the platform.

Byte Dance' s success is attracting big investors. It's reportedly in talks with technology kingmaker SoftBank ( SFTBY) about an investment that would value it at around $75 billion, a huge jump from the $ 20 billion valuation it secured last year. That would make Byte Dance one of the world’s most valuable companies alongside Uber.

8．What can be learnt about TikTok?

A．It has appealed to many foreign users.

B．It's the most popular Chinese app abroad.

C．It's the most successful app of Byte Dance.

D．It allows users to share whatever they like on it.

9．What sets Byte Dance apart from other Internet technology companies overseas?

A．Support from its investors.                         B．Success in social video apps.

C．Greater diversity in contents.                       D．AI technology applied to apps.

10．Which of the following can replace the underlined words "got hooked on” in Paragraph 4?

A．were tired of                                             B．were trapped in.

C．were familiar with                                     D．were attracted by

11．What is the main idea of the text?

A．Tik Tok has beaten other social media apps.

B．China's social media apps are successful globally.

C．Social video apps win popularity around the world.

D．Byte Dance is taking the social media world by storm.

    Plastic-Eating Worms

Humans produce more than 300 million tons of plastic every year. Almost half of that winds up in landfills(垃圾填埋场), and up to 12 million tons pollute the oceans. So far there is no effective way to get rid of it, but a new study suggests an answer may lie in the stomachs of some hungry worms.

Researchers in Spain and England recently found that the worms of the greater wax moth can break down polyethylene, which accounts for 40% of plastics. The team left 100 wax worms on a commercial polyethylene shopping bag for 12 hours, and the worms consumed and broke down about 92 milligrams, or almost 3% of it. To confirm that the worms’ chewing alone was not responsible for the polyethylene breakdown, the researchers made some worms into paste(糊状物) and applied it to plastic films. 14 hours later the films had lost 13% of their mass — apparently broken down by enzymes (酶) from the worms’ stomachs. Their findings were published in Current Biology in 2017.

Federica Bertocchini, co-author of the study, says the worms’ ability to break down their everyday food — beeswax — also allows them to break down plastic. ＂Wax is a complex mixture, but the basic bond in polyethylene, the carbon-carbon bond, is there as well, ＂she explains, ＂The wax worm evolved a method or system to break this bond. ＂

Jennifer DeBruyn, a microbiologist at the University of Tennessee, who was not involved in the study, says it is not surprising that such worms can break down polyethylene. But compared with previous studies, she finds the speed of breaking down in this one exciting. The next step, DeBruyn says, will be to identify the cause of the breakdown. Is it an enzyme produced by the worm itself or by its gut microbes(肠道微生物)?

Bertocchini agrees and hopes her team’s findings might one day help employ the enzyme to break down plastics in landfills. But she expects using the chemical in some kind of industrial process — not simply ＂millions of worms thrown on top of the plastic.＂

43．What can we learn about the worms in the study?

A．They take plastics as their everyday food.

B．They are newly evolved creatures.

C．They can consume plastics.

D．They wind up in landfills.

44．According to Jennifer DeBruyn, the next step of the study is to            .

A．identify other means of the breakdown

B．find out the source of the enzyme

C．confirm the research findings

D．increase the breakdown speed

45．It can be inferred from the last paragraph that the chemical might            .

A．help to raise worms

B．help make plastic bags

C．be used to clean the oceans

D．be produced in factories in future

46．What is the main purpose of the passage?

A．To explain a study method on worms.

B．To introduce the diet of a special worm.

C．To present a way to break down plastics.

D．To propose new means to keep eco-balance.

    Preparing Cities for Robot Cars

The possibility of self-driving robot cars has often seemed like a futurist’s dream, years away from materializing in the real world. Well, the future is apparently now. The California Department of Motor Vehicles began giving permits in April for companies to test truly self-driving cars on public roads. The state also cleared the way for companies to sell or rent out self-driving cars, and for companies to operate driverless taxi services. California, it should be noted, isn’t leading the way here. Companies have been testing their vehicles in cities across the country. It’s hard to predict when driverless cars will be everywhere on our roads. But however long it takes, the technology has the potential to change our transportation systems and our cities, for better or for worse, depending on how the transformation is regulated.

While much of the debate so far has been focused on the safety of driverless cars(and rightfully so), policymakers also should be talking about how self-driving vehicles can help reduce traffic jams, cut emissions(排放) and offer more convenient, affordable mobility options. The arrival of driverless vehicles is a chance to make sure that those vehicles are environmentally friendly and more shared.

Do we want to copy — or even worsen — the traffic of today with driverless cars? Imagine a future where most adults own individual self-driving vehicles. They tolerate long, slow journeys to and from work on packed highways because they can work, entertain themselves or sleep on the ride, which encourages urban spread. They take their driverless car to an appointment and set the empty vehicle to circle the building to avoid paying for parking. Instead of walking a few blocks to pick up a child or the dry cleaning, they send the self-driving minibus. The convenience even leads fewer people to take public transport — an unwelcome side effect researchers have already found in ride-hailing(叫车) services.

A study from the University of California at Davis suggested that replacing petrol-powered private cars worldwide with electric, self-driving and shared systems could reduce carbon emissions from transportation 80% and cut the cost of transportation infrastructure(基础设施) and operations 40% by 2050. Fewer emissions and cheaper travel sound pretty appealing. The first commercially available driverless cars will almost certainly be fielded by ride-hailing services, considering the cost of self-driving technology as well as liability and maintenance issues(责任与维护问题). But driverless car ownership could increase as the prices drop and more people become comfortable with the technology.

Policymakers should start thinking now about how to make sure the appearance of driverless vehicles doesn’t extend the worst aspects of the car-controlled transportation system we have today. The coming technological advancement presents a chance for cities and states to develop transportation systems designed to move more people, and more affordably. The car of the future is coming. We just have to plan for it.

47．According to the author, attention should be paid to how driverless cars can __________.

A．help deal with transportation-related problems

B．provide better services to customers

C．cause damage to our environment

D．make some people lose jobs

48．As for driverless cars, what is the author’s major concern?

A．Safety.                                                      B．Side effects.

C．Affordability.                                            D．Management.

49．What does the underlined word ＂fielded＂ in Paragraph 4 probably mean?

A．Employed.                                                B．Replaced.

C．Shared.                                                     D．Reduced.

50．What is the author’s attitude to the future of self-driving cars?

A．Doubtful.                                                  B．Positive.

C．Disapproving.                                            D．Sympathetic.