1 . The “diet” in diet drinks maybe a false promise for some soda lovers. True, they deliver the taste of a soda experience, without the calories. Yet, new research shows they can also leave people with increased appetite.
A study published recently in JAMA Network open adds to the evidence that drinks made with sucralose, an artificial sweetener (甜味剂), may increase the appetite among some people. “We found females and overweight people had greater brain reward activity after consuming the artificial sweetener,” says study author Katie Page, a physician at the University of Southern California. Both groups ate more food after consuming drinks with sucralose, compared with after regular sugar-sweetened drinks. In contrast, the study found males and people of healthy weight did not have an increase in either brain reward activity or hunger response, suggesting they’re not affected in the same way.
One theory is that it’s not the artificial sweetener itself that has a direct effect on the body. The idea is that artificial sweeteners may confuse the body by tricking it into thinking sugar is coming. “You are supposed to get sugar after something tastes sweet,” explains Swithers, “Your body has been used to that.” But the sugar never arrives, which may lead to the body’s less efficiency in processing sugar that s consumed later.
Swithers’ lab has also documented that when animals with a history of consuming artificial sweeteners get real sugar, their blood sugar levels rise higher than those of animals not fed artificial sweeteners. “It’s a small effect, but overtime this could contribute to potentially significant consequences,” she says. If this is happening in some people who consume diet soda, it could add to the risk of Type 2 diabetes (糖尿病), because when blood sugar rises, the body has to release more insulin (胰岛素) to absorb the sugar. “So what you’re doing is that you are kind of pushing the system harder,” Swithers says.
1. What can we learn from Katie page’s study?| A．Females enjoying diet drinks consume more food. |
| B．Artificial sweeteners help males with better appetite. |
| C．Diet drinks increase hunger response of healthy people. |
| D．people consuming sucralose have greater brain reward activity. |
| A．The effect of sugar. | B．Response to sweetness. |
| C．Artificial sweetener. | D．The absence of sweetness. |
| A．More insulin release helps sugar level rise. |
| B．people drinking diet soda hardly absorb sugar. |
| C．Type 2 diabetes mainly results from artificial sweeteners. |
| D．Consuming artificial sweeteners might cause health problems. |
| A．The potential of artificially-sweetened drinks. |
| B．The wisdom of choosing healthy sweet drinks. |
| C．The underlying link between diet drinks and health. |
| D．The differences among artificially-sweetened drinks. |
2 . Naturalist Enzo Suma, who is now 40, lives in Puglia, a region in southern Italy whose long coastline faces the Adriatic Sea. Floating waste accumulates in this relatively enclosed part of the Mediterranean, unlike the open ocean, where the waste tends to be spread over a vast area. Feeling concerned about that, Suma makes it a habit to pick up the washed-up waste along the shore, especially after big winter storms.
One day, Suma was walking along the beach near his home when he discovered a bottle of Coke. Suma noticed on the bottle that the price, clearly printed on the bottom, was in lire, a currency (货币) that hadn’t been used in Italy since it was replaced by the euro in 2002. Could a plastic container have well survived in the Mediterranean, he wondered, for about two decades?
That led him to founding the Archeoplastica museum. It has a collection of about 500 unique pieces recovered from Italian shores and the Coke bottle is the first one of them. All collection demonstrates the unsettling life force of plastic waste in the environment. “Seeing that a product people may have used 30, 40, or 50 years ago remains still unchanged, you’ll feel different. It’s a great shock,” Suma said to a reporter. So Suma often exhibits selected pieces from the Archeoplastica collection at local schools around his hometown of Ostuni.
“The playful side of the work allows you to arrive at the less beautiful side of things,” Suma acknowledged. “Plastic is a kind of useful substance. But it’s unthinkable that a water bottle, made from a material designed to last so long, can be used for just a few days—or even minutes—before becoming garbage. Clean the beaches. Clean the oceans. Recycle. But if we are still throwing out plastics, none of those are going to be long-term solutions.”
1. What’s Suma’s concern about his living place?| A．Its long coastline is disappearing. | B．Big storms frequently hit the area. |
| C．Floating waste spreads over a vast area. | D．The waste pollution on shore is worsening. |
| A．They have a history of more than half a century. |
| B．They were quite valuable before turning into waste. |
| C．They’re more like educational exhibits than garbage. |
| D．They have stronger life force than ordinary plastic products. |
| A．Creative, devoted and socially responsible. | B．Enthusiastic, ambitious and adventurous. |
| C．Generous, cautious and humorous. | D．Curious, efficient and playful. |
| A．The birth of plastics has greatly served humans. |
| B．The key to tackling the plastic pollution is to stop littering. |
| C．The plastic problem can be solved by cleaning and recycling. |
| D．People should be more aware of the powerful functions of plastics. |
3 . Chinese scientists have discovered a new water reservoir on the moon in the form of glass beads (珠子), which could have major significance for finding out the water content of the earth’s only natural satellite and potentially extracting them to support future lunar missions.
A study published in the journal Nature Geoscience last week revealed soil samples collected by China’s Chang’e-5 lunar probe contained impact glass beads that held water in the form of hydroxyl——a molecule consisting of one oxygen atom and one hydrogen atom. Hydroxyl ion (离子) is one of the most common ions found in water.
These glass beads are created when meteoroids (流星体) hit the moon’s surface, throwing up hot molten droplets which then cool and turn solid. They function like a sponge, soaking up hydrogen atoms carried by the solar wind to form hydroxyl, thus playing an important role in the water cycle of the lunar surface.
While each bead only holds a tiny amount of water, these glass balls can be seen everywhere on the moon and researchers estimated lunar soils could store as much as 270 billion metric tons of water. For decades, scientists thought the moon was bone dry until discoveries in recent years revealed its soil could hold water. “The moon potentially holding 270 billion metric tons of water is quite substantial, though it pales in comparison to the amount of water in the earth’s oceans,” said Hu Sen, a researcher from the Institute of Geology and Geophysics of the Chinese Academy of Sciences and one of the key scientists behind the study.
These findings not only provide insight on the origins, storage, and transportation of water on celestial bodies without atmospheres, but they also may prove helpful for planning and building a sustainable human habitat on these planets, he added.
However, the specific origins of the water on the lunar surface remain a mystery. The study presented several potential sources, including solar wind implantation, the release of trapped gas when the moon was hot and volcanically active, and delivery by comets and asteroids.
1. What is the use of the glass beads?| A．Absorbing water. | B．Drying water. |
| C．Creating water. | D．Recycling water. |
| A．The moon was a dry place for decades. |
| B．The moon holds as much water as the earth does. |
| C．Scientists discovered the moon could store water. |
| D．The amount of water on the moon is comparatively large. |
| A．Trapped gas should be released. |
| B．Further research needs to be done. |
| C．Water sources have been identified. |
| D．Solar wind was implanted on the moon. |
| A．Future Habitat for Humans: the Moon. |
| B．New Discovery: Glass Beads on the Moon. |
| C．New Findings: Water on the Lunar Surface. |
| D．Future Missions: China’s Chang’e Lunar Probes. |
4 . Reshaping the world for a fossil fuel-free future means working quickly. Climate scientists say carbon emissions must stop by 2025 to minimize environmental damage. And by designing computational materials together with makers who can build and test them quickly, scientists can rapidly develop technologies like more powerful solar cells and car batteries.
Michael is the name of a supercomputer devoted to just one task―discovering the ultimate battery system. Researchers at University College London will use Michael to digitally build and test prototypes (原型) in every new material and type of cell possible to improve battery life, performance and price.
Finding a resilient (弹性的) design for solid-state batteries would be a huge breakthrough for electric vehicles and energy storage. Lighter, longer-lasting and cheaper solid-state technology could vastly improve vehicle range and charging time. And the energy from solar and wind power could be more efficiently stored until ready for use.
Scientists working in the US and the UK led the way in the 1970s in developing the lithium-ion (锂离子) battery used in today’s electric cars, laptops and cameras, But commercial units were only developed once the Japanese electronics giant pushed the technology forward for mass production. Partnerships between companies and universities could ultimately crack solid-state battery design. Oxford University and some companies are looking to win the international race to create a durable product. But they are only one among many.
Replacing liquid used in lithium-ion batteries with a solid conductor may take large digital processing. Electric vehicle makers are working with a computer giant to find successful designs that may include cheap and plentiful materials found in seawater. An electric vehicle maker is partnering with NASA to open a solid-state battery plant that uses no rare or expensive metals. The plan is to create a large database of materials that can be mixed and matched for the best combinations.
But computational materials may be needed in virtually every industry. And by rapidly classifying millions of substances on their ability to conduct electricity, their toughness, or the way they reflect light, AI and supercomputers can speed up the process of creating materials for just about anything.
1. What message does paragraph 1 convey?| A．It’s too fast to design computational materials. |
| B．It’s too late to reshape the fossil fuel-free world. |
| C．Developing green energy can reduce carbon emissions. |
| D．Developing technology can speed up carbon emissions. |
| A．Heavy and solid. | B．Light but breakable. |
| C．Less-costly and workable. | D．Expensive but efficient. |
| A．To show the weakness of mass production. |
| B．To show the good trend of the cooperation. |
| C．To show the difficulty of the battery design. |
| D．To show the development of British technology. |
| A．Michael Is Devoted to Storing Solar Energy |
| B．Companies and NASA Will Push Technology Forward |
| C．Electric Vehicle Makers Are Struggling to Solve Air Pollution |
| D．Supercomputers and AI Can Create Future Low-carbon Industries |
5 . My 5-year-old daughter Kai walked around a bus stop, picking up candy wrappers and plastic bottles and throwing them in the waste bin. We were a visiting family here, but she was cleaning the sidewalk, which didn’t shock me, nor was I
Our cleanup project began when we drove past an empty field one day and Kai
However, it seems we can never
Now Kai hopes to become a marine biologist to protect sharks one day. She still has many years to
The last time our family was at the beach, we still picked up plastic bottles. Most
| A．embarrassed | B．discouraged | C．concerned | D．frightened |
| A．apologized | B．confirmed | C．spotted | D．explained |
| A．loose | B．magic | C．processed | D．abandoned |
| A．trade | B．mistake | C．replace | D．change |
| A．pulled over | B．blew up | C．turned down | D．gave in |
| A．due to | B．ahead of | C．other than | D．instead of |
| A．official | B．serious | C．optional | D．regular |
| A．deliver | B．remove | C．track | D．produce |
| A．stress | B．comfort | C．anger | D．pride |
| A．mess | B．platform | C．court | D．house |
| A．scary | B．pleasant | C．historic | D．real |
| A．decide | B．struggle | C．survive | D．contribute |
| A．safe | B．giant | C．distant | D．sick |
| A．personally | B．memorably | C．technically | D．universally |
| A．promise | B．threat | C．reminder | D．favor |
6 . If you had boarded a passenger plane in 1950, you would have seen five people in the cockpit (驾驶舱): two pilots, a radio operator, a navigator and a flight engineer. Over the years, technical advances have gradually removed the need for the last three, leaving just two pilots. That has been the norm (标准) in commercial aviation for decades.
However, things could be simplified further — one of the two remaining pilots could soon go. Many military aircraft are already manned by a single pilot, and for commercial aviation this would mean stepping into a brave new world.
But how will airlines make this brave innovation come true? One way is to greatly increase automation in the cockpit, devoting more tasks to computers. Another is to shift the same tasks from the cockpit to the ground. “The latter approach seems to be more workable, at least in the short term, because much of what is required already exists,” says Patrick Smith, an airline pilot flying Boeing 767 aircraft. “A trained ground operator could observe a number of flights at once and even fully control the plane remotely if needed.”
It’s true that single-pilot operations could help airlines save money, but there is another reason which makes them quicken their pace for this crucial breakthrough. Boeing predicts a need for 600,000 new pilots in the next two decades, but by some estimates, there will be a deficit (赤字) of at least 34,000 pilots globally by 2025. Reducing the number of pilots on some crews or aircraft could lessen the impact of this.
Perhaps the biggest barrier to a single pilot will be selling the idea to passengers. In 2019, Don Hairis, a professor at Coventry University, conducted a survey on the prospect of flying on an airliner with just one pilot. Just a minority of participants said they’d be willing to take that flight, and the general idea was that removing a pilot increased the possibility of accidents. In the study, Harris concluded that the single-crew airliner would be still probably 20 years away.
1. What is the potential trend in commercial aviation according to the text?| A．It will make air travel eco-friendly. |
| B．It will switch to single-pilot operations. |
| C．It will tighten its flight control for safety concerns. |
| D．It will bring in many military aircraft to the industry. |
| A．Raising the standards in admitting new pilots. | B．Making pilots adaptable to different situations. |
| C．Using computers to automate the flight process. | D．Gaining piloting support from ground operators. |
| A．The shortage of pilots. | B．The need for new airlines. |
| C．The airlines’ brave innovation. | D．The financial problem airlines face. |
| A．The prospect of single-crew airliners is bright. |
| B．It's urgent that airlines reduce airplane accidents. |
| C．Passengers are willing to try new types of airplanes. |
| D．Airlines have a long way to go before the innovation occurs. |
7 . James Warren rides the public bus a lot in his hometown of Denver. Then in January, Warren spotted a woman waiting for a bus. There was no seating at the stop—and no sidewalk—so she sat in the dirt. So he decided to build a bench.
“I just took some scrap wood and went to town,” Warren said. He then realized that one bench was far from enough. There are more than 9,000 bus stops in the Denver metro area, many of them without seating or shelter. Warren carves “Be kind” on each one—each made from scrap wood he finds in construction waste containers.
“I met some ladies the other day who were talking about how they used the benches every day,” Warren added. “It fills me up. It’s air in my tires.”
Warren said many people have hopped on his bench—making bandwagon, which has motivated him to build more. “I’ve had a lot of people reach out to me on Twitter,” he said. “Some people have wanted to come and help me.” Others saw Warren’s work in the local news and decided to take out their tools, too. People also started donating supplies. “That puts me over the moon,” Warren said.
Nica Cave, 26, a Denver mobility advocate, said, “The lack of infrastructure, shelter and seating at transit stops marginalizes(边缘化) those who rely on public transit. People like Warren are really encouraging me to see how people are willing to use their own time and resources to provide these much-needed services.” Cave added that she hopes the local government will see Warren’s benches and get involved.
That is precisely Warren’s goal. Warren—who is planning to organize a bench-building workshop—said his hope is that his benches make a difference in his community and even beyond. “My goal is to make people’s lives just a little bit better.” Warren said.
1. What do we know about Warren’s benches?| A．They are carved with his name. | B．They can be found at any bus stop. |
| C．They are specially designed for women. | D．They are made of recycled materials. |
| A．It is the source of my effort. | B．My tires are almost flat. |
| C．I need to fill air into my tires. | D．Praise is the best reward for me. |
| A．The good sales of the benches. | B．The assistance from other people. |
| C．The comments on Twitter. | D．The awards from the local government. |
| A．To earn more money to live a better life. |
| B．To set up his own bench-building workshop. |
| C．To encourage people to use more public transit. |
| D．To make people live a little bit better. |
8 . “Just sign here, sir,” the deliveryman said as he handed Oscar Reyna a package.
The package consisted of a long, narrow box
Oscar was 16 when he first saw the
Oscar
Oscar talked his grandparents into going by Mrs. O’Brien’s house on their way home. He rang the bell, the door opened, and an elderly woman appeared. “May I
“I’d like to return it if it’s yours,” Oscar said,
“Why, yes! It’s mine,” replied Mrs. O’Brien with a
“No, ma’am,” he said. “My grandmother says that a good deed is its own reward.”
“Well, that’s
Years later Oscar was staring at the finely carved handle of the umbrella as he remembered Mrs. O’Brien. It was in perfect condition, considering how
As if
| A．strictly | B．carefully | C．roughly | D．casually |
| A．Opening | B．Seizing | C．Observing | D．Searching |
| A．After | B．When | C．Since | D．Although |
| A．average | B．unusual | C．plain | D．typical |
| A．designer | B．seller | C．user | D．owner |
| A．convinced | B．forced | C．encouraged | D．advised |
| A．until | B．before | C．which | D．where |
| A．invite | B．help | C．bother | D．know |
| A．putting up | B．turning out | C．picking up | D．holding out |
| A．wide | B．confident | C．proud | D．shy |
| A．patience | B．kindness | C．courage | D．determination |
| A．obviously | B．naturally | C．exactly | D．probably |
| A．old | B．rare | C．precious | D．nice |
| A．in contrast | B．in return | C．in exchange | D．in answer |
| A．attractive | B．significant | C．unselfish | D．sympathetic |
9 . Trent Johnson just celebrated his graduation from medical school in Ohio with a ceremony at his parents’ home in Florida.
He
His friends
His twitter where the video immediately went
“I remember seeing my face on the newspaper and thinking I not only became a doctor, but I motivated people all over the world to
Johnson was brought up in an underdeveloped area where people would have
As Johnson settles into his new surroundings, he will continue to spread his message of hope and
| A．recognized | B．learned | C．anticipated | D．recalled |
| A．sorrowful | B．pitiful | C．awkward | D．guilty |
| A．permitted | B．begged | C．appointed | D．helped |
| A．consistently | B．virtually | C．casually | D．formally |
| A．standard | B．origin | C．popularity | D．atmosphere |
| A．memory | B．option | C．moment | D．design |
| A．virtual | B．mad | C．wild | D．blank |
| A．evaluated | B．featured | C．engaged | D．promoted |
| A．change | B．start | C．sacrifice | D．follow |
| A．scary | B．awful | C．incredible | D．specific |
| A．low | B．powerful | C．rare | D．noble |
| A．heal | B．escape | C．reform | D．serve |
| A．pioneer | B．chemist | C．physician | D．professor |
| A．seldom | B．just | C．still | D．yet |
| A．admiration | B．innovation | C．cooperation | D．inspiration |
10 . From the time I was seven, I had a dream of becoming a member of the students’ union. I always
What were the points that would work in my favour? I had good grades, and I was friendly and helpful. I would not allow my plain appearance to
I loved making friends and I liked being helpful, so I decided that perhaps I could use these
The day after the election, when the head teacher
| A．admired | B．remembered | C．praised | D．believed |
| A．planning | B．praying | C．considering | D．judging |
| A．almost | B．gradually | C．hardly | D．quite |
| A．took | B．educated | C．provided | D．meant |
| A．Once | B．Until | C．As | D．Although |
| A．put | B．leave | C．hold | D．fight |
| A．speech | B．chance | C．dreams | D．plans |
| A．people | B．qualities | C．ways | D．attitudes |
| A．reach | B．present | C．show | D．repeat |
| A．attended | B．prepared | C．reminded | D．ran |
| A．discussed | B．admitted | C．announced | D．promised |
| A．nodded | B．cheered | C．gathered | D．waited |
| A．achieved | B．celebrated | C．devoted | D．developed |
| A．rely on | B．take in | C．look for | D．stand by |
| A．brighten | B．bless | C．expand | D．enrich |
