1 . The scientists who re-engineered the plastic-eating enzyme (酶) PETase have now created a new enzyme called “cocktail”, which can digest plastics up to six times faster.
PETase breaks down PET back into its building blocks, creating an opportunity to recycle plastics and reduce plastic pollution. PET is the most common thermoplastic (热塑性塑料) used to make single-use drink bottles and it takes hundreds of years to break down in the environment, but PETase can shorten this time to days. The initial discovery set up the prospect of a revolution in plastic recycling, creating a potential low-energy solution to deal with plastic waste.
Now, the same trans-Atlantic team have combined PETase and its “partner”, a second enzyme called MHETase, to generate much bigger improvements: simply mixing PETase with MHETase doubled the speed of PET breakdown, and engineering a connection between the two enzymes to create a “super-enzyme” increased this activity by a further three times.
The team was co-led by the scientists who engineered PETase, Professor John McGeehan and Dr Gregg Beckham. Professor McGeehan said: “Gregg and I were chatting about how PETase attacks the surface of the plastics and MHETase chops things up further, so it seemed natural to see if we could use them together. Our first experiments showed that they did work better together, so we decided to physically link them. It took a great deal of work, but it was worth the effort -we were delighted to see that our new enzyme is up to three times faster than the separate enzymes.”
The original PETase enzyme discovery indicated the first hope that a solution to the global plastic pollution problem might be within grasp, though PETase alone is not yet fast enough to handle the tons of PET bottles. Combining it with a second enzyme, and finding together they work even faster, means another leap forward has been taken towards finding a solution to plastic waste. PETase and the new combined MHETase-PETase both work by digesting PET plastic. This allows for plastics to be made and reused endlessly, reducing our reliance on fossil (化石) resources.
1. What can we learn about “cocktail” from the text?| A．It doubles the breakdown of plastics. |
| B．It takes hundreds of years to break down. |
| C．It deals with plastic waste three times faster. |
| D．It contributes to breaking down plastics quickly. |
| A．A new study of PET. |
| B．The breakdown of PET. |
| C．The discovery of PETase. |
| D．The function of PETase. |
| A．Combining PETase and MHETase works better than separate ones. |
| B．Conducting experiments requires no diligent work. |
| C．PETase chops things up further. |
| D．MHETase attacks the surface of the plastic. |
| A．PET pollution is no longer a difficult problem to deal with. |
| B．The new enzyme is speeding up our reliance on fossil resources. |
| C．MHETase-PETase makes the world free from plastic pollution. |
| D．Plastic-eating enzyme “cocktail” promises new hope for plastic waste. |
2 . Darius Brown’s passion for animals is matched only by his love of bow ties (蝴蝶领结), and the 12-year-old in Newark, New Jersey decided to combine the two into something useful. Brown’s organization, Beaux and Paws, dresses shelter pets up in fancy bow ties made by himself, so the animals can look good while seeking adoption.
Brown was diagnosed with comprehension delay, speech delay and fine motor skills delay when he was only two years old, and over time, his family encouraged his creativity as he developed his love for animals and fashion.
His mother, Joy Brown, and sister Dazhai Brown Shearz noticed a breakthrough for Brown when he turned eight while his sister was admitted to a cosmetology school. There, he began to cut materials and learned to sew to help make his sister hair ribbons.
“With his fine motor skills delay, he wasn’t able to really use his hands well—tying a shoe was challenging,” Brown-Shearz said. “My mother and I came up with the idea that if he helped us with things like preparing the ribbon or cutting it and sewing materials together, it would help him. And it did—it worked!”
Shortly after, Brown began making his own bow ties and wore one nearly every day. Strangers would stop Brown to ask him where they were sold. It was then that Beaux and Paws achieved success. Brown has since donated hundreds of bow ties to animal shelters throughout the country and is now in the process of fundraising to provide even more of them for dogs and cats who are looking for a home.
The young businessman has even been acknowledged by a famous leader, who sent him a letter speaking highly of him for his work. “Dear Darius,” the letter began. “After hearing your story, I wanted to reach out to commend you for your commitment to community service. From founding Beaux and Paws to lifting up the lives of those around you, it’s clear you are doing your part to look out for your fellow citizens.”
1. What was Brown fond of at an early age?| A．Fancy motors. | B．Speech and sports. |
| C．Animals and fashion. | D．Reading books. |
| A．Tying a shoe. | B．Learning to sew. |
| C．Breaking a record. | D．Being admitted to a school. |
| A．To prove his ability. |
| B．To win respect of others. |
| C．To help animals get adopted. |
| D．To be a successful businessman. |
| A．Praise. | B．Help. | C．Educate. | D．Respect. |
3 . Vaccines may soon make their first film(薄膜) appearance. Led by expert Maria A. Croyle, researchers have developed a thin sheet that preserves vaccines for long periods without refrigeration. This means the carefully cooled small bottles now used to ship vaccines could potentially be replaced by lightweight films that can be mailed in an envelope and stored on a shelf.
The film is tailored to suit each specific vaccine candidate and provide a protective coating. “We’ve learned over time that the key to really stabilizing whatever the film holds is to have it intermixed with all the components,” Croyle says, adding that the process is quick and uses affordable and standard equipment. “We really wanted to come up with something that would be transferable to developing countries.”
Immunization(免疫) programs depend heavily on keeping vaccines cold (2℃-8℃) as they are transported, sometimes over thousands of kilometers to faraway locations. Delivery can be difficult and costly, and transport disruptions can cause the vaccines to be ineffective.
But this new product can store live viruses, bacteria and antibodies for several months at 20℃. In a paper published in Science Advances, the scientists show that the live viruses in one vaccine were preserved in the film even after 36 months. They also find that a flu vaccine suspended in their film compares favourably with a traditional flu shot. “The study demonstrates early proof of concept for an exciting platform for vaccine product development,” says Lisa Rohan, a pharmacologist, who was not involved in the study. She also notes that each vaccine type would need a custom formulation(配方) for future stages of development.
Finding partners to mass-produce for clinical trials is the researchers’ most pressing problem, Croyle says. They are also exploring packaging methods to keep their films stable up to 40℃.
Size is a major advantage—a letter-sized sheet of the film can carry more than 500 doses of vaccine, about 1⁄900 the weight of the same amount of traditional doses. By making it easier and cheaper to ship and preserve vaccines efficiently, Croyle says, the technology could vastly improve immunization rates the world over, particularly in middle to low income countries.
1. What can we learn about the film?| A．It contains animal’s DNA. |
| B．It will replace vaccines. |
| C．It comes in different flavours. |
| D．It can hold bio-products. |
| A．Its transportation requirement. |
| B．Its development schedule. |
| C．Its possible advantages. |
| D．Its key components. |
| A．advise personalizing vaccines. |
| B．suggest the product is promising. |
| C．prove the study is supported widely. |
| D．stress the functions of a new platform. |
| A．Immune system will be improved a lot all over the world. |
| B．A new type of affordable vaccine will benefit low-income countries. |
| C．Vaccines would be transferable to developing countries. |
| D．A new type of film preserves vaccines for long periods without being cooled. |
4 . 4 UK Campsites with availability for summer 2021
Sands Caravan and Camping park
Right on a sandy beach, this site has wide-open views of the sea. Choose from gentle walks exploring the coast to exciting hikes in the Torridon mountains. Well-kept facilities include a shop, indoor cooking and eating areas and a games/TV room.
$22 for tent, car and 2 aduls, $3 child.
Swanns Bridge Glamping
For a back-to-nature stay with creature comforts, Swanns Bridge is a good choice. It’s surrounded by impressive scenery. There’s a choice of furnished yurts, bell tents and cabins. The team can arrange boating, surfing and other water sports on the river or sea.
Cabins sleep 2 from $75 a night, yurts sleep 2 from $90, bell tents sleep 4 from $95.
Ling’s Meadow
This campsite on a family-run farm offers a real escape, with plentiful animals to spot. With a maximum of 25 people on the site at one time, everything revolves around nature and the green ethos (理念): waste water is recycled on the farm.
Camping $12/$6 a night for adult/child, under-3s free, 20% off stays of seven nights or longer.
Walesby Forest
Walesby Forest is a non-profit outdoor adventure centre which usually hosts school groups, but this year is offering public camping in woodland surroundings. The huge choices of activities offered, from water sports to climbing, make it a great choice for families.
Camping from $10 a night adult, $8 child, under-4s free.
1. Which is suitable for those who prefer to cook for themselves?| A．Sands Caravan and Camping park. |
| B．Swanns Bridge Glamping. |
| C．Ling’s Meadow. |
| D．Walesby Forest. |
| A．$ 210. | B．$ 168. | C．$126. | D．$ 100.8. |
| A．Water sports. | B．Hiking. | C．Cycling. | D．Climbing. |
5 . At only 9 years old, Lesia Cartelli was badly burnt in a gas explosion at her grandparents’ house. The burns were so severe that her own grandfather didn’t recognize her. Lesia could have remained withdrawn for her whole life. But now, this woman uses her painful past to help other burn victims find healing (治愈). “My life got better when I started to look at my life as a gift,” Lesia said.
Lesia started Angel Faces, a national nonprofit organization offering week-long supportive retreats (休养所) for adolescent female burn victims. These retreats, for girls ranging from ages 11-19, provide seminars to help the girls heal emotionally (情感上).
“She’s like a ball of sunshine,” said Casi Smith, a 17-year-old with burns on her face she received as a baby. “Looking at her, I can see everything she’s been through. But here she is; instead of hiding, she’s helping people. To me, that is amazing. I don’t know if I could ever do that.”
As a woman burned in a gas explosion, Lesia is able to connect with these young ladies on a personal level, as someone who knows what they’re going through. Her heart for helping others motivates fellow burn victims to take control of their circumstances.
All of these women are miracles. They are blessed to have survived horrible accidents most of us can’t even imagine. Yet, surviving the incident is just the beginning. Lesia describes the period following the actual event causing the burns as a “trauma cocoon”.
And that’s where she steps in.
“I didn’t want any other girl to go through what I had gone through,” she says. “We offer a place where the girls can suffer less pain and begin to really heal.”
1. What made Lesia’s life become better after the accident?| A．Her grandfather’s timely help. | B．Angel Faces’ supportive retreats. |
| C．The change of her attitude to life. | D．Other burn victims’ healing stories. |
| A．Angel Faces provides help for all female burn victims. |
| B．Lesia started Angel Faces with the help of Casi Smith. |
| C．Victims receive Angel Faces’ professional medical help. |
| D．Lesia’s experiences have inspired many young burn victims. |
| A．The challenging time that pushes one forward. |
| B．The quiet place where one can have great fun. |
| C．The physical injury that can be easily removed. |
| D．The time when one feels painful and withdrawn. |
| A．Powerful and caring. | B．Creative and adventurous. |
| C．Selfish but brave. | D．Shy but independent. |
6 . One minute, Peggy Lewis and her husband were watching the trees blow in the wind outside their home. The next minute, they were surrounded by pieces of glass from the house’s broken windows. The roof tore off and the walls caved in. After the 152-mph tornado had passed, it took a team of neighbors to pull the couple from the rubble (瓦砾) and take them to the hospital. “I thought we were going to die,” says Lewis, 58. It was an unbelievable natural disaster in the United States.
When the pair returned to their home three days after that awful night last June, it was clear that the house would need to be cleared out. But before that, she wanted one thing-her family Bible (圣经). Lewis bought the Bible 35 years ago at the start of her marriage. Like many folks, she’d used it to hold and keep her family’s history.
The Bible was the first thing Lewis looked for when she returned to the house. It was on top of an antique dresser in her bedroom when she’d last seen it. In fact, the dresser wasn’t there at all. When two volunteers showed up to help the couple dig out, Lewis had one request for them: “If you can find anything, please find my Bible”.
After an hour of searching, a volunteer ran up to her. She cried loudly looking at the book in her hands. The young woman had found the Bible while searching through the rubble. Stunningly, while many books inside the home had been destroyed beyond recognition, the Bible was still perfect, even though it had sat in the rain for days. “I completely broke down,” says Lewis. “I thought it was gone forever. It was a miracle.”
Even slowly, the treasures reappeared in her life. The Bible and her treasures in it actually lived through the terrible disaster.
1. What happened to Peggy Lewis?| A．She lost her family after a tornado. | B．A tornado destroyed her house. |
| C．Her house survived the tornado. | D．She benefited a lot from the disaster. |
| A．Repair their house. | B．Protect volunteers from rain. |
| C．Explore the value of the Bible. | D．Hunt for a family Bible. |
| A．Unluckily. | B．Worryingly. | C．Surprisingly. | D．Interestingly. |
| A．To inform. | B．To educate. | C．To persuade. | D．To instruct. |
7 . OHIP covers part or all of the following services:
Doctors
Whether you visit your doctor, or if you see one in a walk-in clinic, OHIP covers the full cost of your services-as long as they're medically necessary.
Hospital visits and stays
If you need to go to the hospital, OHIP covers:
● doctor and nursing services
● services to check what's wrong
● medicine for in-patients
● some medicine for out-patients
If you want a private or semi-private room, you or your private insurance will have to pay some or all of those hospital fees.
Dental surgery in hospital
Some dental surgeries need to be performed in a hospital because they are complex and/or you have another medical condition that needs monitoring during the procedure.
OHIP covers in-hospital dental surgeries such as:
● tumor removal
● rebuilding surgeries
● medically necessary tooth removal
Optometry (eye-health services)
OHIP covers the cost of one major eye exam every 12 months, plus any minor assessments you need, but only if you are:
● 19 years and younger
● 65 years and older
When you are 20 to 64 years old, OHIP may also cover a major eye exam if it has been requested for a specific reason by your doctor.
You may be qualified for additional eye care if you are on the Ontario Disability Support Program (ODSP) or Ontario Works.
1. How can patients pay hospital fees in a private room?| A．By OHIP. | B．By medical donation. |
| C．By themselves. | D．By auto insurance. |
| A．Because they are too complex to accomplish. |
| B．Because they need lots of medical facilities. |
| C．Because doctors are afraid of medical accidents. |
| D．Because doctors need monitor patients' condition. |
| A．You're a member of OHIP. | B．You're a member of Ontario Works. |
| C．You're on the Ontario Dental House. | D．You're on the Ontario Support Program. |
8 . Table-Waiting Robot Cat
A table-waiting robot cat built by a Chinese technology firm can carry plates of food, navigate a restaurant, miaow(喵喵叫) at dinners—and even react to having its ears stroked.
Making its debut(初次露面) at the 2020 Consumer Electronics Show in Las Vegas, the so-called BellaBot was built for Chinese restaurants lacking enough waiters. It is the brainchild(智慧结晶) of the Chinese robotics and artificial intelligence firm PuduTech.
It features four shelves in the center of its tower-like body to carry plates. Having been loaded up with meals by its human colleagues, the cat-themed robotic waiters miaows when it delivers food to diners to encourage them to take their plates. If customers thank BellaBot by stroking its ears, it will initially respond with a look of pleasure on its on-board screen, which displays animations of a cat's face. “The owner’s hand is so warm,” BellaBot has been programmed to respond.
However—much like a real cat—the robot’s reaction soon changes if it is petted for too long. “It gets mad to remind you not to interrupt its job,” the designers introduced. The BellaBot waiter robot is a more personality-rich update to PuduTech’s previous model, which featured a more utilitarian(实用主义的) design and user interface.
Both BellaBot and its predecessor were designed with a particular mind to Chinese restaurateurs which are often short of waiting staff.
In a real-world food-service setting, however, BellaBot may find it difficult to operate at peak times. Nevertheless, restaurants are anticipated to increase their reliance on automation—whether in the form of robotic waiting staff or otherwise.
Furthermore, improvements in technology will see consumer robot designs grow steadily better at communicating with humans.
1. In what way can the cat robot serve as a waiter?| A．By serving food to the customers in time. |
| B．By stroking its ears to express its pleasure. |
| C．By sending food on the shelves set in its body. |
| D．By loading up meals with its human colleagues. |
| A．Delight. | B．Anger. | C．Surprise. | D．Anxiety. |
| A．To attract more customers. |
| B．To liberate humans from busy labor. |
| C．To advance the development of technology. |
| D．To help to solve the shortage of human labor. |
| A．They can cook the delicious food. |
| B．They can talk with the customers better. |
| C．They will replace the human waiters completely. |
| D．They will be fond of the customers’ long-time petting. |
9 . Electronic waste, also known as e-waste, consists of a discarded phones, printers, TVs, electric toothbrushes and many other electronic goods no longer in use.
A shocking 53. 6 million tons of electronic waste was generated worldwide in 2019 — less than a fifth of which was recycled, according to UN's Global E-waste Monitor 2020 report.
Of the total e-waste last year, Asia contributed the biggest amount — 46.4 per cent — followed by the Americas(24.4 percent), Europe (22.3 percent), Africa (5.4 percent) and Oceania (1.3 percent).
The combined heap of e-waste for 2019 averaged 7. 3 kg for every man, woman and child on Earth. The UK averaged the second-biggest in the world, at 23.9 kg, behind Norway, which averaged 26kg.
The report also reveals that just 17.4 percent of the e-waste was properly collected and recycled. E-waste is a health and environmental hazard (危害), containing hazardous substances such as mercury, which damages the human brain.
After a device is discarded and e-waste is warmed up, toxic chemicals are released into the air, damaging the atmosphere. E-waste in landfills can also seep (渗透) toxic materials into groundwater, affecting animals and plants.
Gold, silver, copper, and other high-value materials were collectively valued at $57 billion. However, they were mostly dumped or burned rather than being collected for treatment and reuse. In countries with developing markets, an increasing number of household electronics like refrigerators, air conditioners, and lamps are now being bought, leading to the rapid increase in e-waste. A global obsession with smart phones, which tend to be replaced by an updated model after a year, also helps build e-waste piles.
It's not that countries don't have policies to fight e-waste since 2014, the number of countries that have adopted a national e-waste policy has increased from 61 to 78, the report says. But advances are slow, enforcement (执行) is poor, and policies fail to encourage the collection and proper management of e-waste. The lack of effective policies around the world needs to be addressed (解决) as soon as possible.
1. According to official figures, how much e-waste was recycled in 2019?| A．53.6 million tons. | B．10.8 million tons. |
| C．9.3 million tons. | D．20.1 million tons. |
| A．health condition | B．electronic products |
| C．energy resources | D．environmental protection |
| A．Tolerant. | B．Indifferent. | C．Ambiguous. | D．Critical. |
| A．E-waste is increasing. | B．E-waste is being reduced. |
| C．E-waste is harmful to people. | D．E-waste is being encouraged. |
10 . A proud and happy all-female Delta flight crew lit up the skies earlier last October, flying 120 female students from Salt Lake City to NASA in Houston for tours of the facilities and to meet with female leaders in the industry.
The flight was part of the airline’s Women Inspiring our Next Generation (WING) program, which was created in 2015 to help close the gender gap in aviation (航空) and expose more young girls to STEM(Science, Technology, Engineering and Math) careers. This is the fifth WING flight, with more than 600 female students flying Delta so far through the program.
The flight was planned and executed (执行) completely by women, including pilots, ramp agents, gate agents and flight control.
“At Delta, we believe you have to see it to be it, “said Beth Poole, general manager of pilot development, who helped start Delta’s WING initiative, in a statement. “We’re taking ownership to improve gender diversity by exposing girls at a young age and providing a pipeline so that 10 years from now, they will be the pilots in the Delta cockpit (驾驶舱) inspiring generations of women who follow. ”
While the students, who ranged in age from 12 to 18, were in Houston, they met with female mentors in aviation. They toured NASA’s Mission Control Center, Johnson Space Center and other key facilities in areas of flight and space exploration.
“It didn’t seem realistic to go after a career in aviation, but today I realized, ‘Hey, I can do this too’, ” said Katelyn J, age 17, a 12th grader from Advanced Learning Center.
Delta has achieved 100% pay parity for employees in frontline jobs. In the past four years, 7. 4%of the airline’s newly hired pilots have been women. The WING program is one of the ways they’re hoping to increase those numbers.
“I’ve loved being able to look at all of the things these successful women have accomplished, ” said Shanae C., 17, a 12th grader from Jordan Technical Institute. “I think we ill learn from them and build on their foundation of success.”
1. What can we know from this text?| A．Female pilots receive their training at the early age. |
| B．More and more female pilots will take males’ place. |
| C．Male pilots are more likely to have air crash than female pilots. |
| D．The WING program is intended to train more youngsters in STEM. |
| A．Minority. | B．Diversity. | C．Equality. | D．Majority. |
| A．A poster. | B．A travel brochure. | C．A novel. | D．A newspaper. |
| A．The Gender Gap Is Closed | B．The Sky Has No Limit |
| C．Female Pilots Are Better Than Males | D．Gender Discrimination Exists in Aviation |
