1 . Chinese scientists recently achieved precise total synthesis (合成) of sugar from carbon dioxide in the laboratory, marking a crucial step in artificial sugar synthesis.
The synthesis, which took more than two years to realize, was achieved by teams from the Chinese Academy of Sciences’ Tianjin Institute of Industrial Biotechnology and the academy’s Dalian Institute of Chemical Physics. Their research was published last week in a paper in Chinese Science Bulletin, a multidisciplinary academic journal.
Sugar is a major source of energy for the human body and a key raw material for industrial production, and it is mainly obtained by extracting it from crops such as sugar cane. However, the traditional method of extraction is limited by the energy conversion efficiency of plant photosynthesis. Moreover, the process of extracting sugar has been affected by uncertain raw material supplies due to land degradation and shortages, ecosystem degradation and extreme weather and natural disasters caused by global warming.
As a result, artificial sugar synthesis has been continually studied by the scientific community in recent years, and scientists around the world have contributed to the effort. In their latest research, the Chinese scientists adjusted high-concentration carbon dioxide and other raw materials in the reaction solution. With the help of chemical catalysts and enzyme (酶) catalysts, they obtained four kinds of sugars: glucose, allulose, tagatose and mannose.
The experiment lasted about 17 hours, much shorter than the time required for traditional methods of sugar extraction, according to Yang Jiangang, lead author of the paper and associate researcher at the Tianjin institute.
The efficiency of sugar synthesis in this study was 0.67 grams per liter per hour, which was more than 10 times higher than the previous results achieved by scientists worldwide. Yang said that the carbon dioxide to sugar conversion rate of glucose reached 59.8 nanomoles of carbon per milligram of catalyst per minute. This is the highest level of artificial sugar production known domestically and internationally.
The study also achieved precise control of artificial sugar synthesis. “By controlling the varied catalytic effects of different enzymes, theoretically almost any type of sugar can be synthesized,” Yang said. Regarding the study, Manfred Reetz, a member of the German National Academy of Sciences Leopoldina, said it is a particularly challenging task to convert carbon dioxide into sugars.
The achievement by Chinese scientists has provided a flexible, multifunctional and efficient sugar synthesis route, which opens a door for green chemistry, Reetz said. Green chemistry, similar to sustainable chemistry, is a rapidly developing field that focuses on how to fully utilize raw materials and energy in the process of producing the intended product while minimizing or eliminating the use and generation of harmful substances.
Carbon dioxide to sugar conversion is seen as an example of green chemistry, since it was conducted under normal temperature and pressure conditions and did not yield any harmful substances.
1. Why do scientists keep studying artificial sugar synthesis?| A．Because sugar is an essential energy source for industrial production. |
| B．Because the traditional extraction approach is not environmentally friendly. |
| C．Because raw material supply is unreliable in the process of traditional sugar extraction. |
| D．Because the traditional extraction approach is less productive than plant photosynthesis. |
| A．It synthesized almost all types of sugar in the laboratory. |
| B．It controlled varied catalytic effects of different enzymes. |
| C．It converted high-concentration carbon dioxide into sugar. |
| D．It lasted 17 hours, shorter than previous traditional methods. |
| A．Green chemistry helped use up all raw materials to generate more products. |
| B．Carbon dioxide to sugar conversion will be used in industrial production soon. |
| C．Green chemistry is a new field where Chinese scientists will put more efforts on. |
| D．Carbon dioxide to sugar conversion will take up all sugar production due to its efficiency. |
Last year, I baked biscuits for complete strangers to say “thank you”. I’d had to call 999 because I found my husband unconscious on the floor. Within minutes, a police car arrived and soon my husband received medical care in hospital.
A week later, when I dropped off still-warm biscuits and presented a thank-you note at the police station, the policemen thanked me for delivering gifts.
I drove away feeling light and happy. Later, I realized that my natural high might have been more than it seemed.Research has shown that sharing gratitude has positive effects on health. People who express gratitude will increase their happiness levels, lower their blood pressure and get better sleep.
What about people who receive gratitude?Research has confirmed that when people receive thanks, they experience positive emotions.“Those are happy surprises,”says Jo-Ann Tsang, a professor of psychology. When someone is thanked,he’s more likely to return the favor or pass kindness on, and his chances of being helpful again doubles, probably because he enjoys feeling socially valued.
The give-and-take of gratitude also deepens relationships. Studies show that when your loved ones regularly express gratitude,making you feel appreciated,you’re more likely to return appreciative feelings, which leads to more satisfactory in your relationships.
Nowadays,however,many people don’t express gratitude. Our modern lifestyle may be to blame. With commercial and social media, everything is speeding the younger generation to feel they’re the center of the world. If it’s all about them, why thank others?
Why not thank others? Just take a look at how many positive effects can saying “thank you”have on personal health—and the well-being of others.
If you aren’t particularly grateful, I strongly suggest you learn to be.People who are instructed to keep gratitude journals,in which they write down positive things that happen to them,cultivate gratitude over time.
1. What health benefits can people gain from expressing gratitude?2. How do people probably respond when they receive gratitude and feel socially valued?
3. Please decide which part of the following statement is false, then underline it and explain why.
▷ Saying “thank-you”improves relationships,but nowadays some young people don’t want to do it because everything is making them feel blamed by the whole society.
4. If possible, who would you like to express gratitude to most? Why? (In about 40 words)
Read what Sarah writes in reply to Paul.
1. What problem does Paul have?
| A．He worries about his career life. | B．He considers himself not creative. |
| C．He has difficulty understanding things. | D．He will fail his course however hard he works. |
| A．She doesn’t get why Paul is afraid. |
| B．She believes each question has the right answer. |
| C．She thinks people should often reflect on their ideas. |
| D．She thinks people should think freely without fear of judgement. |
| A．Paul and Sarah are strangers | B．Paul and Sarah have the same idea |
| C．Paul and Sarah are college classmates | D．Paul and Sarah are from the same place |
4 . Writing across Time
When students today need to take notes, they simply reach for their ballpoint pens. For students in the past, writing instruments were not so convenient.
Quill pens
Quill pens were made from large bird feathers. Students sharpened the quills with knives and then dipped them into pots of ink to write. The points needed constant re-sharpening and each dip of the quill provided only enough ink to write one word. Besides these problems, drops of ink often stained the page. Yet, people used quill pens for more than a thousand years. Can you imagine writing with a quill pen?
Brush pens
Chinese students traditionally used brush pens to practice writing characters. Unlike quill pens, brush pens had soft bristles that made smooth lines. Students dipped their brush pens in a pool of ink on an inkstone and then wrote.
Chalk
In the 19th and early 20th centuries, when paper was not easily available, chalk was widely used in classrooms. Teachers wrote with chalk on blackboards while students practiced writing and maths on their own slates (石板).
Fountain pens
Fountain pens were the first pens that stored ink inside, from where it flowed through the metal tip or nib (笔尖) for writing. In the 19th century, they finally replaced quills on school desks. However, even with fountain pens, ink still often spilt out, leaving stains everywhere.
Ballpoint pens
Early ballpoint pens leaked and wrote poorly. Three inventors took almost sixty years to finally solve these problems in the early 1950s. Today two of them, Hungarian journalist Josef Laszlo Biro and French Baron Bich, are known for making the ballpoint pen cheap and reliable. Biro and Bic pens are still hugely popular and useful today.
1. The passage mainly talks about ______.| A．the origins of writing instruments | B．the quality of writing instruments |
| C．the development of writing instruments | D．the materials of writing instruments |
| A．Quill pens. | B．Brush pens. |
| C．Ballpoint pens. | D．Fountain pens. |
| A．save ink and paper | B．cost less and work well |
| C．leak when used | D．write poorly |
| A．provide information | B．give advice |
| C．offer an opinion | D．tell a story |
5 . Young students are often considered “digital natives,” with technology integrated into every aspect of their lives. While this can be an advantage in some situations, research has shown that the impact is not entirely positive—the Internet allows them to quickly find information at the cost of significant distraction in class. Without being attentive, students will be incapable of processing information, which means they’re not going to be able to understand, analyse, criticise and come to some decision about the information.
When students can’t seem to focus, a common idea among teachers is that short is good. Many teachers simply cut lessons into smaller pieces. Some teachers begin classes with mindfulness exercises when students need to concentrate. However, it turns out that any sort of “tech breaks” could counteract the desires to come back to study.
Some teachers also choose to “meet students where they are” on platforms like YouTube. A 2018 study from Pearson found that students tended to stay away from physical books, preferring video as a source of information second only to teachers. By meeting students where they already engage and create, teachers can better catch attention.
However, while some educators are welcoming technology in the classroom, multiple studies have shown more traditional classrooms can be more successful. A 2014 study found taking notes in longhand helped students withhold information better than using a laptop. Researchers also point out switching between short teaching pieces too quickly could take valuable comprehension from the students. Students need time to engage with a topic before moving on.
Even many tech advocates find value in traditional methods and suggest an integrated learning. They agree teachers’ authority remains vital and the face-to-face interaction between students and teachers is still the primary component in the classroom. Technology will be favoured only when it improves a lesson in ways that are impossible offline.
Success is no longer about knowing the most. Instead, it’s the ability to think critically and creatively, the very skills that digital media weakens by lowering attention spans. If you think of people who became successful in the tech world, it wasn’t because they could code; it was because they could think. Digital natives will continue to eagerly adopt new media. Teachers have no choice but to upgrade themselves, not only to ensure students can access and take advantage of new technologies, but to educate students to succeed in a world constantly trying to distract them.
1. What result has technology brought to students?| A．It urges them to process information. |
| B．It prevents them obtaining information. |
| C．It ruins their possible classroom distraction. |
| D．It damages their ability to digest information. |
| A．Maintain. | B．Motivate. | C．Reduce. | D．Replace. |
| A．Direct instruction takes priority in lessons. |
| B．Digital resources will weaken offline learning. |
| C．Small lessons can engage students in learning. |
| D．Laptop noting helps students gain knowledge better. |
| A．Students need to learn to get rid of social media. |
| B．Teachers should progress to educate the young generation. |
| C．The benefits of technology on education outweigh its harm. |
| D．Traditional methods are favoured by both teachers and students. |
6 . How to Study More Effectively
No matter whether you are preparing for some specific course, a professional degree, or an entrance exam, it’s important to maximize study time and improve the efficiency of study.
You can also cut your study time into short sessions. Your most productive studying typically occurs within the first 25 to 30 minutes of hitting books, so try to study in 30 minutes, and take a 5—10 minute break, so that you are able to absorb and consolidate the information.
Studying isn’t only spending hours and hours on list of what you think will be on an exam or quiz.
Following the suggestions to study more effectively will mean shorter and more efficient study sessions, and eventually, better grades!
| A．You can quiz yourself whenever possible. |
| B．Effective studying starts with the right attitude. |
| C．It is important to study in a smart way and go the extra mile. |
| D．Study with friends or classmates and question each other on the material. |
| E．You are more likely to do well before a quiz when you have time to review. |
| F．Creating a schedule is the first and most important thing to maximize your study time. |
| G．This is why a certain balance should be made and studying time should be cut into shorter sessions. |
