1 . Smartphones, tablets and other digital devices can be addictive. They affect sleep. They draw kids into an alternate universe, often distracting（使分心）them from more productive-and healthier-real-world activities. And they are often linked to anxiety and depression, learning disabilities and obesity（肥胖）. Yet for many teenagers, cellphones and social media are also absolutely necessary tools for planning their social lives, keeping up with schoolwork and staying in touch with out-of-town friends and relatives.
How can parents make the most of the constructive uses of screen-based technology while minimizing its harmful effects？
The key is helping kids use technology as a tool, not a toy, “where there’s some purpose other than the medication of boredom,” says Jim Taylor, a psychologist and author of the book Raising Generation Tech：Preparing Your Children for a Media-fueled World. Taylor, like many other medical and mental health professionals, advises parents to set limits and stick to them. They should restrict the amount of time their kids spend on devices, create tech-free zones-no cellphones in their bedrooms, for example-and tech-free times, such as at the dinner table, in restaurants and on family outings.
Perhaps the best thing you can do is serve as a good role model by exhibiting the same online behavior you expect of your children, says Dr. Elias Aboujaoude, a Stanford University psychiatrist. “If parents are breaking their own rules,” Aboujaoude says, “kids cannot be expected to behave differently.”
Chad Landgraf, 44, of Oklahoma, told me he was worried about how addicted his 12-year-old son and 5-year-old daughter became when they were on their devices. So, hoping to set an example, he switched from e-books to old-fashioned print. “When I had my Kindle or ipad open, they. didn’t know if I was reading or surfing the net,” Landgraf says. “But at least if I have a paper copy of a book, they know I am reading. Modeling seems like the easiest way.”
1. What may be the result of children’s using digital devices?| A．Health improvement. | B．Free creation. |
| C．Sleep disorder. | D．Good conduct |
| A．Killing time by using screen-based technology. |
| B．Forbidding kids using smartphones. |
| C．Setting clear boundaries for kids. |
| D．Restricting tech-free family time. |
| A．He was afraid of becoming addicted. | B．He expected to be a role model. |
| C．He was tired of surfing the net. | D．He preferred paper copies of books. |
| A．Parenting in a digital world | B．Learning to be intelligent parents |
| C．Using smart devices wisely | D．Helping children behave themselves |
2 . Happiness is not a warm phone, according to a new study exploring the link between young life satisfaction and screen time. The study was led by professor of psychology Jean M. Twenge at San Diego State University (SDSU).
To research this link, Twenge, along with colleagues Gabrielle Martin at SDSU and W. Keith Campbell at the University of Georgia, dealt with data from the Monitoring the Future (MtF) study, a nationally representative survey of more than a million U. S. 8th-, 10th-, and 12th-graders. The survey asked students questions about how often they spent time on their Phones, tablets and computers, as well as questions about their face-to-face social interactions and their overall happiness.
On average found that teens who spent more time in front of screen devices — playing computer games, using social media, texting and video chatting — were less happy than those who invested more time in non-screen activities like sports, reading newspapers and magazines, and face-to-face social interactions.
"The key to digital media use and happiness is limited use," Twenge said. "Aim to spend no more than two hours a day on digital media, and try to increase the amount of time you spend seeing friends face-to-face and exercising — two activities reliably linked to greater happiness."
Looking at historical trends from the same age groups since the 1990s, it's easy to find that the increase of screen devices over time happened at the same time as a general drop-off in reported happiness in U. S. teens. Specifically, young peopled life satisfaction and happiness declined sharply after 2012. That's the year when the percentage of Americans who owned a smartphone rose above 50 percent. By far the largest change in teens' lives between 2012 and 2016 was the increase in the amount of time they spent on digital media, and the following decline in in-person social activities and sleep.
1. Which method did Twenge's team use for the study?| A．Calculating students' happiness. |
| B．Asking students certain questions. |
| C．Analyzing data from a survey. |
| D．Doing experiments on screen time. |
| A．By making a comparison. |
| B．By giving an example. |
| C．By making an argument. |
| D．By introducing a concept. |
| A．To draw a conclusion from the study. |
| B．To offer some advice to the readers. |
| C．To prove social activities' importance. |
| D．To support the researchers' finding. |
| A．Quitting Phones Equals Happiness |
| B．Screen Time Should Be Banned |
| C．Teens' Lives Have Changed Sharply |
| D．Screen-addicted Teens Are Unhappier |
3 . The COVID -19 pandemic has changed life as we knew it just a few weeks ago. Millions of people worldwide are now under required or voluntary lockdowns. All public attractions, including museums and aquariums, are closed, and the usually crowded streets of popular tourist destinations are empty. An unexpected silver lining during these challenging times for humans is that many animals are finally getting a chance to leave their normal habitats and move about freely.
The first animals to take advantage of human absence were Annie and Edward, two penguins who live at Chicago’s Shedd Aquarium. A video released on March 15, 2020, showed the couple eagerly duckwalking around, exploring the aquarium's various exhibits. The video, which instantly became popular, inspired other institutions to share short videos of their four-legged creatures playing as well.
The Cincinnati Zoo in Ohio joined the fun trend on March 16, 2020，with a “Home Safari” live-stream series-the first staring its adorable baby panda，Fiona. “Let us help make your children's hiatus from school fun and educational,” zoo officials announced. “Join us for a Home Safari Online Live each weekday at 3 pm，where we will highlight one of our amazing animals and include an activity you can do from home.
Meanwhile，the San Diego Safari Park has kept their webcams（网络摄像头）rolling，allowing fans to enjoy lovable animals without leaving home. Animals in the wild are also lively as humans stay indoors. The absence of cruise ships is bringing large numbers of dolphins to a port in Cagliari，while groups of wild turkeys are happily walking on the streets of Oakland.
Though the animals indeed appear to be having a good time，the heartwarming videos and images shared on social media, are also bringing much -needed cheer to millions of humans worldwide. Stay strong and healthy! We are all in this together!
1. What changes has the COVID-19 pandemic caused to the zoo animals?| A．They are now under required or voluntary lockdowns. |
| B．They can enjoy a free life without tourists' disturbance. |
| C．They will be faced with unexpected existing challenges. |
| D．They get a chance to wander about freely in the wild. |
| A．Courses. | B．Sightseeing. | C．Activities. | D．Interruption. |
| A．To enable people to admire animals at home. |
| B．To film the animals wandering about in the zoo. |
| C．To compete for more viewers online. |
| D．To record people's life in the COVID-19 crisis. |
| A．The Pandemic Affects the World |
| B．Lovely Animals Bring fun to People |
| C．Animals Play in the Absence of Humans |
| D．Stay Strong and Healthy in the Pandemic |
4 . During a decline in tourism, one national park in Thailand has seen a dramatic rise in “visitors” recently. So many are the hermit crabs （寄居蟹）flooding into the otherwise empty beaches of Koh Lanta that shells （贝壳）for them to live in have become in short supply.
The Thai government moved quickly to ease the housing shortage, launching a public appeal for empty shells that netted over 200 kg. On December 5 these were distributed around the park in a ceremony.
Hermit crabs rely on shells to protect their soft bodies, moving to larger shells as they grow. On Koh Lanta and the surrounding smaller islands, their rapid increase seems to be a natural phenomenon, rather than directly related to the absence of tourists. But the shortage of shells may be man-made：pretty ones have long been gathered to be sold as goods. Crabs had begun to make do with potential death-traps such as plastic caps and bottles.
The shell drive was part of a government initiative to “regain the balance of nature”. “I have instructed all national parks to do whatever it takes,” says Varawut Silpa-archa, the minister for natural resources. His inspiration comes from the pause in tourism brought on by CO VID-19. A ban on international visitors and the closure of national parks have helped nature recover, bringing endangered leatherback turtles back onto Thai beaches. In the coastal provinces of Phang Nga and Phuket, turtles have laid the largest number of eggs for 20 years.
The government has decided to try to copy the short break forced on it by CO VID-19 in future. From now on, all national parks will be required to close for a short period during the off-season and to limit the number of tourists through a reservation system when they are open. Although such restrictions mean reduced earnings from tourism in the short term, in the longer run more parks may help to keep the tourists coming.
1. What happened to the beaches of Koh Lanta recently?| A．They got flooded by seawater. |
| B．They became completely empty. |
| C．They were packed with hermit crabs. |
| D．They saw a constant stream of tourists. |
| A．Natural disasters. |
| B．Human activities. |
| C．Their preference for bottles. |
| D．The government's involvement. |
| A．To warn turtles are dying out. |
| B．To prove beaches are their ideal habitats. |
| C．To stress ecological diversity of Thailand. |
| D．To illustrate the birth of Varawut’s inspiration. |
| A．Developing Economy or Protecting Animals? |
| B．Closing National Parks or Drawing More Visitors? |
| C．Governments are Responsible for the Balance of Nature |
| D．Authorities Help to Find Shelters for Homeless Hermit Crabs |
5 . Plastic remains one of the most-used materials for making many of the things we use in our everyday lives. Things made of plastic can be very strong and last a long time. They also do well in extreme heat and cold. Plastic is also much lighter than metal and can be easily formed into different shapes. This makes the material perfect for the uses across many different industries
But the widespread use of plastics is causing major problems for the environment. Plastic materials are causing serious damage to the world’s oceans.
Plastics can take hundreds of years to break down on their own. Very few kinds are highly recyclable. This is because of the way plastics are formed. Even when recycling is possible, the process is costly and can use a lot of energy.
But a team of researchers working at the U.S. Department of Energy say they have created a kind of plastic that could lead to products that are 100 percent recyclable.
The researchers say the new material is a plastic polymer(聚合物)called polydiketoenamine, or PDK. The team reports that the material can be broken down in parts at the molecular(分子的) level. It can then be built up again to form plastics of different shapes, colors and more. The researchers say this process can be repeated over and over again -without the plastic material losing any performance or quality.
“Most plastics were never made to be recycled,” lead researcher Peter Christensen said. “But we have discovered a new way to make plastics that takes recycling into consideration from a molecular point of view. Then we would be able to remove plastics from the oceans. It’s going to be a really exciting time.”
1. What's the purpose of the first paragraph?| A．To show the advantages of plastic |
| B．To explore the future of plastic |
| C．To prove we can’t live without plastic |
| D．To introduce different plastic products |
| A．What they are used for | B．How they are formed. |
| C．The deep ocean | D．The high cost |
| A．It can be used repeatedly. |
| B．It can hardly be broken down. |
| C．It is a colorful plastic polymer. |
| D．It is used in some countries now. |
| A．Plastic and industry. |
| B．Pollution and environment. |
| C．Plastic: a most-used material. |
| D．PDK: a new recyclable plastic. |
6 . Sugar cane（甘蔗）contains around 10% sugar. But that means it contains around 90% non-sugar—the material known as bagasse （甘蔗渣）which remains once the sugar-bearing juice is squeezed out. World production of cane sugar was 185 million tonnes in 2017 , which results in a lot of bagasse.
At the moment, most of it is burned. But Zhu Hongli, a mechanical engineer at Northeastern University, in Boston, thinks it can be put into better use. As she, and her colleagues describe, in Matter this week, with a bit of improving bagasse makes an excellent and biodegradable （可生 物降解的）replacement for the plastic used for disposable food containers such as coffee cups.
Dr. Zhu is not the first person to have this idea. But previous attempts tended not to survive contact with liquids. She knew from previous research that the main reason why past efforts fell to pieces when wet is that bagasse is composed of short fibres which are unable to hold the finished product. She therefore sought' to insert a suitably long-fibred substance.
Bamboo seemed to be the best choice. It grows quickly /degrades readily and has appropriately long fibres. And it worked. When the researchers blended bamboo remaining into bagasse, they found that the result had a strong crossing of short and long fibres.
To put their new material through its paces, Dr. Zhu and her colleagues first poured hot oil onto it and found that, rather than passing through the material, as it would have with previous, bagasse products, the oil was resisted by their invention.
They also found that when they made a cup out of the stuff and filled it with water heated almost to boiling point, the cup remained unbroken for more than two hours. Though this is not as long as a plastic cup would Hast, it-is long enough for all practical purposes.
1. What do we know about bagasse?| A．It is widely used. | B．It is usually wasted. |
| C．It can not be degraded. | D．It takes up 10% of sugar cane. |
| A．The cups are not disposable. | B．The fibres of bagasse are short. |
| C．The plastic can not be replaced. | D．The material is not biodegradable. |
| A．It can let oil pass through. | B．It can be boiled in the water. |
| C．It can hold liquid and resist heat. | D．It can reduce the use of bamboo. |
| A．New Bamboo Containers | B．A New Application of Fibres |
| C．Young and Promising Materials | D．A Perfect Mix of Cane and Bamboo |
7 . The best and most-commonly used sources for the pills we have are oily fish like salmon（畦）， mackerel and sardines. Many environmentalists fear that some species are being over fished for this purpose. We may have an endless voracity for fish oil, but we don't have an endless supply of fish.
Menhaden, which is described as “a big-headed, smelly, foot-long fish" , is in great danger. Although prized for dinner in the 18th century, the species has become the unknown victim of the fish oil business 9 which presents us with potential sea fish. Menhaden filter-feed almost entirely on algae （海藻）and is especially good at changing it into-3 fatty acids, which make them a good target for fish oil companies.
One particular company, Protein of Houston, has been fishing 90 percent of the country' s menhaden. It's become such a big problem that 13 of the 15 Atlantic states have banned the company * s boats from their waters. Yet the company is still allowed to fish in North Carolina and Virginia, as well as federal waters; the company * s efforts result in the removing of half a billion menhaden every year.
Aside from running out a public natural resource for a company，s private profit, the damage to the ecosystem is cause for alarm. The muddy brown color of the Long Island Sound is the direct result of lacking water nitration （过滤）一a job that was once done by menhaden.
Menhaden keep the ocean waters of the Atlantic and Gulf coasts clean. A menhaden filters four to six gallons of water of algae in a minute, which prevents underwater dead zones.
Measures should be taken to avoid the over fished situation. Plant seeds such as flax seed, chiaseeds, hemp seeds, and sesame seeds — and particularly their oils — are good vegetarian sources of omega-3 fatty acids, although the mix of specific acids is different from which one can get with fish.
1. Why does menhaden become a good fish for companies to make pills?| A．It is good at forming-3 fatty acids. |
| B．It feeds mainly on the harmful algae. |
| C．It is well-known for its rich protein. |
| D．It is relatively easy for companies to catch. |
| A．trouble | B．shortage |
| C．resource | D．appetite |
| A．To grow more plants for their seeds to make oil. |
| B．To use some substitutes instead of more fish oil. |
| C．To call on the government to make laws in fishing. |
| D．To take part in more activities to protect the environment. |
| A．The broken natural ecosystem. | B．The process of making fish oil. |
| C．Bad effects of fish oil making. | D．How to use natural resources. |
8 . A wildfire is a fire that burns strongly and out of control in the wild. Wildfires are becoming even more powerful and harmful over time. That is in part because of climate change. Hotter temperatures and drier forests are helping to cause wildfires. The fires start from natural causes, like lightning. Humans can start fires with cigarettes or campfires, accidentally.
Sometimes, people can set fires on purpose. This is to help an ecosystem and those that live there. For thousands of years, humans have set fires on purpose. Fire does put living things in danger, but this happens naturally, Over time, ecosystems have adapted to the benefits from regular fires, because fires clear out dead material. Some plant and animal populations actually need fire to survive and reproduce. The fires help encourage healthy ecosystems. Of course, these are controlled burns. Modern fire experts now know how to set controlled burns that are well planned and safe.
Why is fire necessary? As dead or decaying(腐朽的) plants begin to build up on the ground, they may prevent organisms in the soil from getting nutrients(养分).They may keep animals on the land from getting to the soil. This coating of dead matter can also choke the growth of smaller or new plants.
Fire removes that layer of decay. The soil gets nutrients from the burned material faster than if it had slowly over time. This allows healthy parts of the ecosystem to grow stronger and stronger.
Some plants actually need fire to continue their life cycles. Seeds from some pine trees grow in pine cones that are covered in a thick sap(汁液). The seeds release from the pine cones when fire melts the sap. Fires allow more seeds to get to the soil and grow. The healthier plant populations after a fire can help animals, too Animals that live in nine trees benefit from more growing trees. Plant growth provides the food sources of animals.
Humans should prevent most uncontrolled damaging wildfires. But trying to prevent all fires might make matters worse. Understanding the benefits of fire is the only way to truly keep our ecosystem safe from its dangers.
1. What is the main idea of the first paragraph?| A．The causes of wildfires. | B．The effects of wildfires. |
| C．The functions of wildfires. | D．The characteristics of wildfires. |
| A．To scare dangerous animals away. | B．To encourage healthy ecosystem. |
| C．To offer nutrients to the animals. | D．To control plant and animal populations. |
| A．Humans should prevent all wildfires. |
| B．Plant growth cuts down the food sources of animals. |
| C．Humans are permitted to set forests on fire anytime by law. |
| D．Without fires, it would be difficult for seeds in pine cones to release. |
| A．The Balance of Nature | B．How to Prevent Forest Fires |
| C．How to Protect Our Ecosystem | D．The Ecological Benefits of Fire |
9 . Both IQ and EQ are considered important to our career success. But nowadays, as technology redefines how we work, the qualities we need are developing too. Take adaptability quotient(AQ), a subjective set of qualities loosely defined as the ability to improve in an environment of fast and frequent change.
Every profession will require adaptability and flexibility. Your IQ gets you through the examinations to become qualified for the job. Your EQ helps you connect with an interviewer, land a job, and develop relationships with customers and colleagues. Then, when systems change or aspects of work are automated, you will need AQ to adjust to this change and adapt to new ways of performing your role.
All three quotients are somewhat complementary, since they all help you solve problems and therefore adapt. AQ is now increasingly being sought at the hiring level. While there is no specific method of measuring adaptability like an IQ test, companies are changing their hiring processes to help identify people who may be high in it.
Natalie Fratto, a vice-president at Goldman Sachs, suggests three ways AQ might show in potential candidates: if they can picture possible versions of the future by asking “what if” questions; if they can question incorrect information of an authority; and if they enjoy exploration or seek out new experiences.
Experts say you can work to develop AQ. First, limit distractions and learn to focus so that you can determine what adaptations to make. Second, ask uncomfortable questions to develop courage and normalize fear. Third, be curious about things that fascinate you by having more conversations rather than Googling the answer, something that reduces your ability to solve difficult challenges.
Because of automation, many people in the world may need to be reskilled. We may not all be comfortable with the pace of change—but we can prepare. The ability to learn, change, grow, experiment will become far more important than subject knowledge.
1. What aspect of AQ is mainly talked about in paragraph 2?| A．The definition. | B．The function. | C．The feature | D．The strength. |
| A．drawing pictures | B．learning from authority |
| C．answering what-if questions | D．exploring new possibilities |
| A．Concentrating on our work | B．Avoiding fearful situations. |
| C．Being curious about conversations. | D．Surfing the Internet for information |
| A．AQ Helps Your Success | B．IQ Improves Your Relationship |
| C．New Skills Challenge Your EQ | D．New Technologies Change New Qualities |
10 . Researchers all over the world have been dreaming of “lab-grown” or “cultured” meat, for years. Today, their dream took one step closer to reality as the cultured chicken meat from the US company, Eat Just, has been allowed for sale in Singapore.
Lab-grown chicken is made of real chicken cells, but it's grown in a lab instead of growing in a live chicken.(Cultured meat is different from plant-based meats like the Impossible Burger, Beyond Meat or Quorn, which use plant proteins to create products that just taste very similar to the products made from real meat.)
To grow cultured chicken meat, cells are taken from a real chicken. These cells are then put in a special kind of water that encourages the cells to grow in the lab until they've produced chicken meat——without the chicken.
But many technical challenges of bringing lab-grown meat to the table are far from solved. No one has yet found out how to produce cultured meat even with the same texture and structure of real meat. Even replacing chicken products with lab-grown chicken products that are not very strict with such texture and structure would be a big success for the world.
The existing projects, like Eat Just's in Singapore, can only produce a very small amount of meat for special dishes, while the meat industry kills tens of billions of animals each year. Matching that will be a challenge.
The next challenge is cost. Lab-grown meat is much more expensive than factory farming. "Factory-farmed meat is unbelievably cheap," said Lewis Bollard, who researches animals at the Open Philanthropy Project. “The meat industry doesn't pay for the environmental and the public health problems they have caused. They have managed to produce a product that is just artificially cheap and hard to compete with.”
Although there are still many challenges ahead, today's success in Singapore is cause for celebration.
1. Which company's product is made of animal cells?| A．Quorn. | B．Eat Just. | C．Beyond Meat. | D．Impossible Burger. |
| A．It has been grown in a live chicken. | B．It has the same texture of real meat. |
| C．It still tastes different from real meat. | D．It has been produced in huge amounts. |
| A．Researchers have had a big success in Singapore. |
| B．There are many technical challenges to be solved. |
| C．Cultured meat still cannot compete with real meat. |
| D．Factory-farmed meat is very harmful to our health. |
| A．Cultured Meat Still Faces Too Many Problems |
| B．When Will Lab-grown Meat Become Reality? |
| C．How to Grow Cultured Chicken Meat in a Lab? |
| D．The First Lab-grown Meat to Be on Sale in Singapore |
