【推荐2】The first solar cell capable of powering everyday electrical equipment was made in the 1950s at Bell Labs in New Jersey. Back then the silicon-based(基于硅的) panels were hugely expensive and turned just 6% of sunlight into electricity. Since then, costs have come down dramatically and today’s silicon solar cells can turn up to 22% of sunlight into power. But they’re nearly maxed out in terms of efficiency. Now, perovskites(钙钛矿) offer the potential for dramatic increases in power output, and they could ultimately replace silicon altogether.

Researchers at Oxford PV, a company spun out of the University of Oxford, made a major breakthrough in 2018. By coating silicon with perovskites they achieved 28% efficiency. The company believes it can eventually reach 40%, or higher. “If we want to make all new power generation about solar photovoltaics(光伏), then we need to keep driving the price down,” Henry Snaith, professor of physics at the University of Oxford and co-founder of Oxford PV, said. “One way to do that is to keep pushing the efficiency or power output up, and this is where perovskites really come into play.”

Perovskites were discovered in 1839. Oxford PV uses a synthetic(合成的) version, made from inexpensive materials that are present on the Earth in large quantities, while other companies use variations of the original mineral, collectively called perovskites. As well as improved solar efficiency, they work better than silicon in the shade, on cloudy days or even indoors. Perovskites can be printed using an inkjet (喷墨的) printer and can be as thin as wallpaper. Oxford PV hopes perovskites will eventually replace silicon entirely.

Last month, Saule Technologies’ new factory in Warsaw began printing perovskite solar cells using inkjet printers. Early next year, it will start supplying Swedish construction company Skanska Group. “The material is set to be a game changer in the energy field, because it works in every lighting condition,” said Saule Technologies co-founder Olga Malinkiewicz.

1. What can we say about silicon-based panels?

A．They are incredibly expensive.

B．They have been abandoned totally.

C．They have existed for almost 50 years.

D．They are relatively low in power output.

2. What does Snaith try to stress in paragraph 2?

A．The cost of perovskite solar cells.

B．A key role to be played by perovskites.

C．The applications of solar photovoltaics.

D．A new way to replace solar photovoltaics.

3. What is one of the advantages of perovskites?

A．They exist widely on the Earth.

B．They can be written on like paper.

C．They can be printed with 3-D printers.

D．They perform well in poor lighting conditions.

4. What was expressed in Malinkiewicz’s words?

A．Approval.

B．Worry.

C．Shock.

D．Disappointment.

【推荐3】Billionaire businessman Elon Musk recently confirmed he is still interested in buying the social media service Twitter. The move came after Musk withdrew an earlier offer to buy Twitter for $44 billion. In a recent tweet (推文) on the subject, Musk wrote: “Buying Twitter can greatly support the plan to create X, the everything app.” Musk did not provide details on his brief statement. It has led many people to question what he meant by “the everything app” .

A super app, or what Musk calls an “everything app,” has been described as one that offers a series of services for users. This could include messaging, social networking, direct payment services and online shopping.

One industry estimate shows that Chinese super app WeChat has more than 1 billion monthly users and is a huge part of daily life in China. People can use the app to call up a ride-share or taxi, send money to friends and family or make payments at stores. In 2018, some Chinese cities began testing WeChat for an electronic identification system that would be linked to users’ accounts. Another leading super app across Southeast Asia is called Grab. It offers food delivery, ride-sharing, on-demand package delivery, financial services and investing.

During a question-and-answer event with Twitter employees in June, Musk noted that there is nothing like a super app like WeChat outside of Asia. “You basically live on WeChat in China,” he said, adding that he saw a chance to create such an app.

Adding more tools and services to Twitter could also help Musk reach his high growth goals for the company. During his meeting with employees, Musk said he wanted Twitter to grow from its 237 million users to “at least a billion.”

1. What does “It” refer to in the first paragraph?

A．The tweet.

B．Twitter.

C．An earlier offer.

D．X

2. What is a super app?

A．It offers everything for online users.

B．It has more than 1 billion monthly users.

C．It should be available to users worldwide.

D．It provides services for a huge part of daily life.

3. What do we know about WeChat and Grab according to the text?

A．Grab is the biggest super app in Asia.

B．Both of the apps offer financial services.

C．Only WeChat provide ride-sharing service.

D．WeChat has more monthly users than Grab.

4. Which is not a reason why Elon Musk wants to make a super app?

A．The number of Twitter users is still fast-growing.

B．He gains confidence from WeChat’s success in China.

C．He believes Twitter can be improved to reach the goal.

D．There is little competition for super app market in his country.

【推荐1】There's an organization in England called Playing Out that is trying to send more children outdoors to play. In an ideal world, a child can step outside and enjoy whatever environment he or she encounters. However, many only encounter car-filled streets. Playing Out wants this to change, and its directors invited environmental writer and activist George Monbiot to have a public conversation about how to cope with such a challenge. What follows are some thoughts on the highlights of the conversation,

First, we mustn't underestimate the positive influence of community on a child's wellbeing. It's an essential human need to feel a sense of belonging in a physical space. Monbiot says he gets this sense from his garden, where being in an outdoor physical location connects him with people from all over the community, who are sharing that space.

The greatest threat to modern children's outdoor play is the presence of cars. Monbiot describes neighborhoods where there's minimal traffic. The lines linking houses are closely connected. Compare that to neighborhoods where busy streets bisect (平分) neighborhoods and there's hardly any interaction between households. The busy traffic literally cuts through the threads, and destroys the society's fabric.

This is unfair because children have the right to use land and space as well. But their opinions are ignored when land is being developed. According to Monbiot, children should be allowed to weigh in on how they want neighborhoods to look. He said, "Children have fantastically creative solutions to problems adults can't solve."

Whether it's streets, parks, rivers, or public squares, children need to get out there and fill those spaces with their games, voices and laughter. Not only will it make them healthier, but it'll teach them to be better citizens, knowing how to interact with others and the natural world.

1. What does the underlined word "this" in paragraph 1 refer to?

A．Children's unwillingness to play outside.

B．The possible benefit of outdoor activities.

C．Loss of space for children's outdoor play.

D．The challenge of cutting back on vehicles.

2. How does Monbiot voice his opinion about the power of community?

A．By delivering a public speech online.

B．By describing his personal experience.

C．By explaining the sense of belonging.

D．By giving the result of his research.

3. How does busy traffic affect children's life according to Monbiot?

A．It reduces their access to green spaces.

B．It exposes them to deadly dangers.

C．It increases their knowledge of traffic safety.

D．It threatens their interpersonal connections.

4. Which should be Monbiot's opinion according to the text?

A．Children's voices should be heard in community planning.

B．Children should be allowed to encounter challenges.

C．Vehicles are to blame for children's worsening lives.

D．Vehicles should be reduced to improve people's lives.

【推荐3】Sarah Lynn, an educational consultant and teacher, thinks English learners can improve their ability to remember and use new words by testing themselves. She adds that self-testing improves retrieval(数据检索)--- the ability to use and remember new words.

If you are like most learners, you may have faced such a situation: You think you understand a topic. Yet when asked to use what you have learned, you are not able to remember the information. Not being able to retrieve new ideas could happen on a test or even in a conversation.

Learning takes effort. It takes effort because the learning process changes the brain, says Sarah Lynn. One way it changes the brain is by creating connections, which are called dendrites (树突）. Lynn suggests that dendrite connections are important for retrieval. There are three main ideas about how to grow dendrites and improve retrieval, making connections, using repetition and testing yourself.

Lynn is not the only expert who recommends self-testing. A paper in Journal of Applied Research in Memory and Cognition says one benefit of testing practice is that it improves retrieval. Retrieving information once makes retrieving that information easier in the future. In addition, the paper says, when students test themselves as part of studying, they learn what they do not know. When students know what they do not understand, they can pay attention to overcoming their weaknesses. Lynn recommends that learners test themselves by getting away from what they are studying. Then, they speak something. Lynn suggests reading something or watching a video on the topic, then getting rid of the reading or audio material and summarizing it. This will allow learners to test what they know.

The benefits of such practice, Lynn says, are not just about improving your ability to remember information. By testing yourself, you can build confidence in the skills you have developed. When you test yourself, Lynn says, you will see how much progress you have made. This progress will satisfy and encourage you to do more in the future.

Next time you are studying English, try to test yourself. A simple way to test vocabulary is to create flashcards with clues on one side and the answer on the back. Another way is to use online services to create digital flashcards, through which learners can do a variety of activities based on one set of new words or information. You can match words with meanings, write a word after looking at a picture, or listen to a word and write it. You can also play games with the new words and meanings. Another way is to ask yourself questions at the end of the day, at the end of a study session, or at other times. Lynn recommends that learners ask themselves questions such as, “What did I learn today? What were those words that I thought were interesting? What was that verb tense I learned? How does it work?”

The important point is this: Effective learning takes time, effort and practice. Do not just assume that you can read something once or twice and fully understand it. Even if you highlight important points or take notes in a class, you probably do not fully understand what you learned. After all, Olympic athletes cannot learn how to swim or run just from reading a book. They have to practice swimming or running every day for years. They often compete in races to test their skills. Like those athletes, successful language learners practice as much as they can, and test themselves to improve their skills.

Self-testing is one way to improve your retrieval and inform your future course of study. Give it a try, and let us know how it works for you.

1. According to Sarah Lynn, what's the common situation faced by English learners?

A．They are always forgetting what they have just learned despite their effort.

B．They have to improve their ability both on a test and in a conversation.

C．They don't learn something as well as they thought they did.

D．They don't master ways to improve their skills on a test.

2. What's one benefit of self-testing?

A．Develop people's interest in their study.

B．Improve people's psychological quality.

C．Focus people's attention on their study. .

D．Help people think more critically.

3. Which is the advice given by Sarah Lynn about testing oneself?

A．Present what's learned with the book closed.

B．Remember what's learned by repetitive reciting.

C．Question your teachers on what you doubt bravely.

D．Challenge yourself to make complicated flashcards.

4. Why are Olympic athletes mentioned in the passage?

A．To show how to be successful Olympic athletes.

B．To make people more confident of learning English.

C．To introduce Sarah Lynn's interest in the Olympic Games.

D．To stress the significance of practice in English learning.

5. What's the best title of the passage?

A．Learning actually takes effort most

B．Improving your English by testing yourself

C．Trying your best to memorize more new words

D．Creating connections works best in English learning

【推荐2】Recently, science has been uncovering a link between walking and a lower risk of dementia (痴呆), proving that walking is even good for your brain.     1     Maybe you already love to walk, but you’re getting tired of following your same old route day after day—or maybe you’re new to walking and aren’t sure how to get started. Either way, it’s time to embrace the idea of walking with a purpose.

To get started, sit down with a map and make a plan. Ask yourself, what do you want to get out of walking aside from the health benefits? Do you want to meet other people? See new places? Get out into the wilderness or explore a city?     2    

Making friends and socializing is your goal.     3     Ask your friends where they like to walk and go there, since this will introduce you to new places. Look up your local malls which have groups that come every day, or every weekend, to “walk the mall”. These groups are always happy to include one more walker!

    4     Ask about local hikes that get you out of town and into the wilderness or countryside. Folks who are touring in an RV or car can stop to ask about scenic spots that will get them off the beaten path.

Headed to a new city?     5     Many of our great historic cities offer detailed and well-planned walking tours. You can follow the famous painted red band through Boston’s historic landmarks or walk your way through the sites of Washington, D.C. and Philadelphia.

From the benefits, walking is just plain good for you. Pick up a map and start walking.

A．It’s kind to our bodies and great for our waistlines.

B．Getting away from the crowds is what you’re after.

C．Prepare to get to know the new place from the ground up!

D．It’s also a fantastic way to get fit and to stay in great shape.

E．Call up your friends and schedule walks with them.

F．Nearly any city you can think of offers convenient transportation.

G．Knowing your priorities will help you decide on the type of walk you want to do.