1 . The history of microbiology begins with Dutch cloth maker named Antoni van Leeuwenhoek, a man of no formal scientific education. In the late 1600s. Leeuwenhoek, inspired by the magnifying lenses（放大镜）he used to examine cloth, built some of the first-microscopes. He developed technique to improve the quality of tiny, rounded lenses, some of which could magnify an object up to 270 times. After removing some plaque from between his teeth and examining it under a lens, Leeuwenhoek found tiny twisting creatures, which he called “animalcules”.
His observations, which he reported to the Royal Society of London, are among the first descriptions of microbes（微生物）. Leeuwenhoek discovered an entire universe invisible to the human eye. He found different microbes in samples of pond water, rain water, and human blood. He gave the first description of red blood cells, observed plant tissue, examined muscle, and investigated the life cycle of insects.
Nearly two hundred years later, Leeuwenhock’s discovery of microbes helped French chemist and biologist Louis Pasteur to develop his “theory of disease”. This concept suggested that disease originates from tiny organisms attacking and weakening the body. Pasteur’s theory later helped doctors to fight infectious diseases including anthrax, diphtheria, polio, smallpox, tetanus, and typhoid. All these breakthroughs were the result of Leeuwenhoek’s original work. Leeuwenhoek did not foresee this legacy.
In a 1716 letter, he described his contribution to science this way: “My work, which I’ve done for a long time, was not pursued in order to gain the praise I now enjoy, but chiefly from a strong desire for knowledge, which I notice resides in me more than in most other men. And therefore; whenever I found out anything remarkable, I have thought it my duty to put down my discovery on paper, so that the scientific community might be informed thereof.”
1. Which of the following best describes Leeuwenhoek?| A．trained researcher with an interest in microbiology |
| B．A curious amateur who made pioneer studies of microbes |
| C．A talented scientist interested in finding a cure for disease |
| D．A bored cloth maker who accidentally made a major discovery |
| A．the discovery of microbes |
| B．Pasteur’s theory of disease |
| C．Leeuwenhoek’s contribution |
| D．the origin of the tiny organism |
| A．He admitted that many of his discoveries happened by chance. |
| B．He considered his work to be central to later medical breakthroughs. |
| C．He was greatly concerned with improving people’s living conditions. |
| D．He believed the sharing of knowledge was a key to scientific progress |
a. Magnifying lenses were built.
b. The “theory of disease” was put forward
c. Microbes were discovered in samples of waters.
d. Leeuwenhoek’s first microscopes were successfully developed.
e. Leeuwenhoek explained his thoughts upon his own contribution.
| A．a-d-c-e-b | B．d-a-c-e-b | C．a-c-d-b-e | D．d-a-e-b-c |
2 . A medical capsule robot is a small, often pill-sized device that can do planned movement inside the body after being swallowed or surgically inserted. Most models use wireless electronics or magnets or a combination of the two to control the movement of the capsule. Such devices have been equipped with cameras to allow observation and diagnosis, with sensors that “feel,” and even with mechanical needles that administer drugs.
But in practice, Biomechatronics engineer Pietro Valdastri has found that developing capsule models from scratch (从头开始) is costly, time-consuming and requires advanced skills. “The problem was we had to do them from scratch every time,” said Valdastri in an interview. “And other research groups were redeveloping those same modules from scratch, which didn’t make sense.”
Since most of the capsules have the same parts of components: a microprocessor, communication submodules, an energy source, sensors, and actuators (致动器), Valdastri and his team made the modular platform in which the pieces work in concert and can be interchanged with ease. They also developed a flexible board on which the component parts are snapped in like Legos. The board can be folded to fit the body of the capsule, down to about 14 mm. Additionally, they compiled (编译) a library of components that designers could choose from, enabling hundreds of different combinations. They arranged it all in a free online system. Designers can take the available designs or adapt them to their specific needs.
“Instead of redeveloping all the modules from scratch, people with limited technological experience can use our modules to build their own capsule robots in clinical use and focus on their innovation,” Valdastri said.
Now, the team has designed a capsule equipped with a surgical clip to stop internal bleeding. Researchers at Scotland’s Royal Infirmary of Edinburg have also expressed interest in using the system to make a crawling capsule that takes images of the colon(结肠). One research group, led by professors at the Institute of Digestive Disease of the Chinese University of HongKong, is making a swimming capsule equipped with a camera that pushes itself through the stomach.
One limitation of Valdastri’s system is that it’s only for designing models. Researchers can confirm their hypotheses (假设) and do first design using the platform, but will need to move to a custom approach to develop their capsules further and make them practical for clinical use.
1. According to the passage, Valdastri and his team created the platform to ________.| A．adopt the latest technologies |
| B．make their robots dream come true |
| C．help build specialized capsule robots |
| D．do preciser observation and diagnosis |
| A．Perform live. | B．Run independently. |
| C．Act in a cooperative way. | D．Carry on step by step. |
| A．Valdastri’s system can’t provide a complete capsule creation. |
| B．The modular platform is more useful than a custom approach. |
| C．The capsules can move in human’s body automatically. |
| D．It costs more to module the capsules on the board. |
3 . Babies are surrounded by human language, always listening and processing. Eventually, they put sounds together to produce a “Daddy” or a “Mama”. But what still confuses neuroscientists is exactly how the brain works to put it all together.
To figure it out, a team of researchers turned to a frequent stand-in (代替) for babies when it comes to language learning: the song-learning zebra finch. “We’ve known songbirds learn their song by first forming a memory of their father’s song or another adult’s song. Then they use that memory to guide their song learning,” said Neuroscientist Todd Roberts. “It’s been a long-term goal of the field to figure out how or where in the brain this memory is. This type of imitative learning that birds do is very similar to the type of learning that we engage in regularly—particularly when we’re young, we use it to guide our speech learning.”
Roberts and his team had a feeling that the interface (交叉区域) between sensory areas and motor areas in the brain was critical for this process, and they focused on a group of brain cells called the NIf.
“In order to prove that we could identify these circuits, we thought if we could implant a false memory.” First, they used a virus to cause the neurons (神经元) in the birds’ NIf to become sensitive to light. Then, using a tiny electrode as a flashlight, they activated (激活) the neurons. The length of each pulse of light corresponded with the amount of time the neurons would fire. And the birds’ brains interpreted that time period as the length of each note.
Soon enough, the birds began to practice the notes they had learned, even though they never really heard the sounds. Amazingly, the birds produced them in the correct social situations. The researchers say this is the first time anybody has found exactly a part of the brain necessary for generating the sorts of memories needed to copy sounds.
“This line of research is going to help us identify where in the brain we encode memories of relevant social experiences that we use to guide learning. We know that there are several neurodevelopmental disorders in people that have really far-reaching effects on this type of learning.”
1. The zebra finch is researched because its song-learning mode ________.| A．decides whether it will sing songs |
| B．helps it to say “Daddy” or “Mama” |
| C．is like the way babies learn speech |
| D．reflects its talent for imitating its father’s song |
| A．The interface in the brain. |
| B．Guidance from adults. |
| C．Imitative learning type like birds’. |
| D．The way of regular learning. |
| A．Scientists activated some neurons by using an electrode. |
| B．A bird only sings what it heard before. |
| C．The brain produces tiny electrodes. |
| D．Birds are sensitive to light. |
| A．A change in our way of listening and processing. |
| B．A chance to have relevant social experiences. |
| C．A better knowledge of the secrets of learning. |
| D．Identification of neurodevelopmental disorders. |
4 . Albert Einstein’s 1915 masterpiece “The Foundation of the General Theory of Relativity” is the first and still the best introduction to the subject, and I recommend it as such to students. But it probably wouldn’t be publishable in a scientific journal today.
Why not? After all, it would pass with flying colours the tests of correctness and significance. And while popular belief holds that the paper was incomprehensible to its first readers, in fact many papers in theoretical physics are much more difficult.
As the physicist Richard Feynman wrote, “There was a time when the newspapers said that only 12 men understood the theory of relativity. I do believe there might have been a time when only one man did, because he was the only guy who caught on, before he wrote his paper. But after people read the paper a lot understood the theory of relativity in some way or other, certainly more than 12.”
No, the problem is its style. It starts with a leisurely philosophical discussion of space and time and then continues with an exposition of known mathematics. Those two sections, which would be considered extraneous today, take up half the paper. Worse, there are zero citations of previous scientists’ work, nor are there any graphics. Those features might make a paper not even get past the first editors.
A similar process of professionalization has transformed other parts of the scientific landscape. Requests for research time at major observatories or national laboratories are more rigidly structured. And anything involving work with human subjects, or putting instruments in space, involves piles of paperwork.
We see it also in the Regeneron Science Talent Search, the Nobel Prize of high school science competitions. In the early decades of its 78-year history, the winning projects were usually the sort of clever but naive, amateurish efforts one might expect of talented beginners working on their own. Today, polished work coming out of internships(实习) at established laboratories is the norm.
These professionalizing tendencies are a natural consequence of the explosive growth of modern science. Standardization and system make it easier to manage the rapid flow of papers, applications and people. But there are serious downsides. A lot of unproductive effort goes into jumping through bureaucratic hoops(繁文缛节), and outsiders face entry barriers at every turn.
Of course, Einstein would have found his way to meeting modern standards and publishing his results. Its scientific core wouldn’t have changed, but the paper might not be the same taste to read.
1. According to Richard Feynman, Einstein’s 1915 paper ________.| A．was a classic in theoretical physics |
| B．turned out to be comprehensible |
| C．needed further improvement |
| D．attracted few professionals |
| A．Unrealistic. | B．Irrelevant. |
| C．Unattractive. | D．Imprecise. |
| A．The application of research findings. |
| B．The principle of scientific research. |
| C．The selection of young talents. |
| D．The evaluation of laboratories. |
| A．What makes Einstein great? |
| B．Will science be professionalized? |
| C．Could Einstein get published today? |
| D．How will modern science make advances? |
5 . We’ve all had the experience of wanting to get a project done but putting it off to a later date. So why do we delay things? Are we built to operate this way sometimes?
These questions are central to my research on goal pursuit (追求). It all starts with a simple choice between working now on a given project and doing anything else. The decision to work on something is driven by how much we value accomplishing the project in that moment — what psychologists call its subjective value. And delay, in psychological terms, is what happens when the value of doing something else outweighs the value of working now.
This way of thinking suggests a simple trick to defeat delay. For example, instead of cleaning my house, I might try to focus on why grading papers is personally important to me. It’s simple advice, but sticking to this strategy (策略) can be quite difficult.
People are not entirely wise in the way they value things. For example, a dollar bill is worth exactly the same today as it is a week from now, but its subjective value — roughly how good it would feel to own a dollar—depends on other factors besides its face value, such as when we receive it. The tendency for people to devalue money and other goods based on time is called delay discounting. For example, receiving $100 three months from now is worth the same to people as receiving $83 right now. People would rather lose $17 than wait a few months to get a larger reward.
Getting something done is a delayed reward, so its value in the present is reduced: the further away the deadline is, the less attractive it seems to work on the project right now. The tendency to delay things closely follows economic models of delay discounting. One way to manage it is to make the finish line seem closer. For example, vividly imagining a future reward reduces delay discounting.
1. Which of the following best explains “outweighs” in Paragraph 2?| A．Is equal to. | B．Is greater than. |
| C．Is involved in. | D．Is central to. |
| A．Avoid setting a deadline too strictly. |
| B．Consider doing nothing temporarily. |
| C．Increase the subjective value of working now. |
| D．Realize great fun of working immediately. |
| A．Time and tide wait for no man. |
| B．A bird in the hand is worth two in the bush. |
| C．One of these days is none of these days. |
| D．Don’t count your chickens before they are hatched. |
| A．Asking for nothing in return. |
| B．Lowering our high expectations. |
| C．Searching for instant satisfaction. |
| D．Making future rewards more inviting. |
6 . The vaccine (疫苗) news continues to seem very encouraging. Britain started its mass vaccination effort and the U.S. isn’t far behind.
But there is still one dark cloud hanging over the vaccines that many people don’t yet understand.
The vaccines will be much less effective at preventing death and illness in 2021 if they are introduced into a population where the coronavirus is still severe—as is now the case in the U.S.
A vaccine is like a fire hose (消防龙头). A vaccine that’s 95 percent effective, as Moderna’s and Pfizer’s versions appear to be, is a powerful fire hose. But the size of a fire is still a bigger determinant of how much destruction occurs.
At the current level of infection in the U.S. (about 200,000 confirmed new infections per day), a vaccine that is 95 percent effective—distributed at the expected pace—would still leave a terrible toll (伤亡人数) in the six months after it was introduced. Almost 10 million or so Americans would catch the virus, and more than 160,000 would die.
This is far worse than the toll in a different situation where the vaccine was only 50 percent effective but the U.S. had reduced the infection rate to its level in early September (about 35,000 new daily cases). In that case, the death toll in the next six months would be kept to about 60,000.
It’s worth pausing for a moment on this comparison. If the U.S. had maintained its infection rate from September and Moderna and Pfizer had announced this fall that their vaccines were only 50 percent effective, a lot of people would have panicked.
But the reality we have is actually worse.
How could this be? No vaccine can get rid of a pandemic immediately, just as .no fire hose can put out a forest fire. While the vaccine is being distributed, the virus continues to do damage.
There is one positive way to look at this: Measures that reduce the virus’s spread—like mask-wearing, social distancing and rapid-result testing—can still have great consequences. They can save more than 100,000 lives in coming months.
1. How does the author mainly present his argument?| A．By giving definitions. | B．By categorizing facts. |
| C．By drawing comparisons. | D．By appealing to emotions. |
| A．Improving the effectiveness of the vaccines. |
| B．Producing a greater variety of vaccines. |
| C．Looking at the situation in a positive way. |
| D．Wearing masks and practicing social distancing. |
| A．The vaccines are less effective than expected. |
| B．The US have controlled the spread of the coronavirus. |
| C．The death toll in the next six months will be about 60,000. |
| D．Fewer people will die if the infection rate is lower. |
| A．The vaccine is the hope of wiping out the pandemic. |
| B．The public are optimistic about the effects of the vaccine. |
| C．The public are concerned about the high infection rate. |
| D．The distribution of vaccine will end the pandemic quickly. |
7 . Taste memory is a kind of interesting memory. It is not only the memory of the smell itself, but also the associative memory of the things related to the smell and the emotional memory related to the judgment of the likes and dislikes of the smell. In short, when we smell a familiar smell, our first reaction is to search for the possible source of the smell in our memory - a certain kind of food? Some kind of perfume? Someone? Some place? Even if we smell a strange smell, we will subconsciously look for the smell similar to the smell in our memory.
The particularity of taste is also closely related to our survival instinct - because taste is often associated with food. It is an important survival skill to judge the food's edibility by smell. I have been experimenting with taste aversion(厌恶) memory for a period of time - a taste that has never been encountered and cannot be identified as safe. If there are adverse physiological reactions after eating, I will instinctively avoid this taste the next time I encounter it. This kind of phenomenon will be restrained to a certain extent when it comes to the familiar taste of safety, which is called "potential inhibition", that is, the degree of aversion will be reduced. However, if a person is familiar with the safe taste and has a very serious reaction, this taste will be associated with painful memory, then even if he knows that the taste is safe, he will also involuntarily avoid the food or affect his appetite. This fully shows that taste is not a single memory, but mixed with a large number of other memories.
"People's memory of smell will never be forgotten" - I don't know the origin of this proposition, and it's also too absolute to say that it will never be forgotten - in fact, many diseases lead to people's inability to smell smell, let alone their memory of smell. However, due to the particularity of taste, different taste can not only cause active memory, but also cause a variety of subconscious memory, and also bring a variety of physiological reactions in the body. Therefore, compared with other kinds of memory, it is not easy to forget, which is more reasonable.
1. What can we learn from the first paragraph?| A．Taste memory is a simple memory for the smell itself |
| B．Taste memory is the association and emotional memory related to the smell |
| C．The particularity of taste is closely related to our survival instinct |
| D．We will subconsciously look for similar taste in memory, and it is the same when we feel strange smell |
| A．Taste may be remembered alone |
| B．The potential inhibition occurs in familiar and safe environment |
| C．The safe taste in memory may also have adverse reactions after eating |
| D．The aversion of familiar taste after adverse reaction will be reduced |
| A．in spite of oneself | B．Freewill | C．Autonomous | D．From the heart |
| A．People's perception of smell |
| B．The relationship between smell and people |
| C．Will the memory of smell never be forgotten? |
| D．Research on taste memory |
8 . Oxygen, I'm sure you'd agree, is pretty important for life on Earth. We breathe it in, our cells survive on it and without it, we hardly live. Basically all multicellular life on Earth evolved over millions of years to make use of oxygen.
But take a deep breath, because we need to talk about Henneguya salminicola, a tiny parasite(寄生虫) containing fewer than100 cells that lives within the muscle tissue of salmon, a large fish with silver skin and pink flesh. The strange-looking parasite does not busy itself with such small matters as breathing oxygen. Nope, it seems that H. salminicola is the first multicellular animal we've found that survives without the stuff.
“Aerobic respiration(有氧呼吸) was thought to be commonly found in animals, but now we confirmed that this is not the case, "said Dorothee Huchon, a zoologist at Tel Aviv University in Israel, in a press release.
Huchon and a team of international researchers examined and sequenced(排序) all of. salminicola's' genes in their study, published in the journal Proceedings of the National Academy of Sciences. They found that the parasite, which is closely related to jellyfish, lacks the DNA machinery necessary to“breathe”---it doesn't' have mitochondria(线粒体), often called the "powerhouse" of the cell, because they use oxygen to make energy. It's like a little factory inside almost all cells, and DNA detectives can find mitochondrial genes during sequencing.
The discovery came as something of an accident for the team, who were examining the genome (the complete set of genes) of the species. When they went searching for the mitochondrial genes, they came up empty-handed. "Our discovery shows that evolution can go in strange directions, ”Huchon said. "Aerobic respiration is a major source of energy, and yet we found an animal that gave up this important pathway.”
Some single-celled life forms have evolved the ability to survive without oxygen and do not have mitochondria, either. Plenty of bacteria can exist without oxygen at all. Instead of oxygen, they get their energy from fermentation(发酵) or use other molecules like iron.
But how H. salminicola produces energy is still unclear. Huchon suggests it could draw oxygen from the cells in salmon or it could have evolved similar methods to those of single-celled organisms which scientists have documented in the past.
1. What can we learn about Henneguya salminicola?| A．It is an animal consisting of a cell. |
| B．It can still survive without oxygen. |
| C．It takes on a normal appearance. |
| D．It has a longer lifespan than salmon. |
| A．To make cells breathe fast. |
| B．To help to produce oxygen. |
| C．To provide energy for cells. |
| D．To help cells absorb oxygen. |
| A．Interested. | B．Satisfied. | C．Astonished. | D．Frightened. |
| A．The natural evolution of animal cells |
| B．Different kinds of life forms on earth |
| C．A research on single-celled organisms |
| D．A creature that doesn't breathe oxygen |
9 . It’s late in the evening, time to close the book and turn off the computer. You’re done for the day. What you may not realize, however, is that the learning process actually continues in your dreams.
It might sound like science fiction, but researchers are increasingly focusing on the relationship between the knowledge and skills our brains absorb during the day and the often strange imaginings they generate at night. Scientists have found that dreaming about a task we’ve learned improves performance in that activity (suggesting that there’s some truth to the popular idea that we’re “getting” a foreign language once we begin dreaming in it). What’s more, dreaming may be an essential part of understanding, organizing and retaining what we learn.
While we sleep, research indicates, the brain replays the patterns of activity it experienced during waking hours, allowing us to enter what one psychologist calls a neural (神经的) virtual reality. A vivid example of such replay can be seen in a video researchers made recently about sleep disorders. They taught a series of dance moves to patients suffering from sleepwalking and related conditions. They then videotaped the subjects as they slept. Lying in bed, eyes closed, one female patient on the tape performs the dance moves she learned earlier.
This shows that while our bodies are at rest, our brains are drawing what’s important from the information and events we’ve recently encountered, then integrating that material into the vast store of what we already know. In a 2010 study, researchers reported that college students who dreamed about a computer maze (迷宫) task they had learned showed a 10-fold improvement in their ability to find their way through the maze compared with participants who did not dream about the task.
That study’s chief researcher Herbert Smith suggested that studying right before bedtime or taking a nap following a study session in the afternoon might increase the probability of dreaming about the material. Think about that as you go to sleep tonight.
1. What happens when one enters a dream state?| A．The body continues to act as if the sleeper were awake. |
| B．The neural activity of the brain will become intensified. |
| C．The brain once again experiences the learning activities of the day. |
| D．The brain behaves as if it were playing a virtual reality video game. |
| A．It replaces old information with new material. |
| B．It processes and absorbs newly acquired information. |
| C．It regroups information and places it in different files. |
| D．It systematizes all the information collected during the day. |
| A．Staying up late before finally going to bed. |
| B．Having a period of sleep right after studying. |
| C．Having a dream about anything you are interested in. |
| D．Thinking about the chances of dreaming about the material. |
| A．How study affects people’s dreams. |
| B．Why people learn more after sleeping. |
| C．What time students should study and sleep. |
| D．How dreaming may lead to improved learning outcomes. |
10 . It is an honor for me to deliver this speech and on behalf of the graduating students, welcome you to this special ceremony 2020.
This is a unique moment. We are stepping up to another phase of our lives at a time of great hardship and global difficulties. Hope this ceremony will help erase sad memories, refresh beautiful ones and add more splendid memories into our lives.
I was born in the middle of war, which caused my family to move to Serbia for three years. When the war ended, we returned to Bosnia. My mother, who is and will ever be my heroine, was the only figure who guided me, provided for me and kept me on the right track, in the hope for a better life. I owed her so much as she is responsible for huge part of my success. I will always remember her teachings “to complain less and always find solutions at the price of whatever it takes” ， which brought me to China, an ancient land of new hopes.
During the COVID-19 outbreak, I got the best opportunity to understand China. I saw millions of people united with one goal-to win the battle against this epidemic. I have never seen such a collective dedication from a nation, turning things for the better by sacrificing personal convenience on a grand scale. China's governance and health care system proves to be one of the most efficient in the world. With a population of 1.4 billion, China not only has successfully controlled the transmission of the corona-virus but also assisted many other countries across the globe.
Everyone has a role to play in the battle against the virus. In Tsinghua, I played a tiny but necessary role: Staying on campus, studying online, cooperating during temperature checks and respecting social distancing measures. The rules set by the university and Chinese government had everyone's health and safety as first priority. This made me feel safe and confident that China was on the right track towards victory. Throughout this time, despite the immense challenges, Tsinghua has facilitated many online conferences, which helped me nurture more skills in my field of study.
Friends, we are now graduating from one of the world’s most prestigious universities. Tsinghua has been like a mother to us over the past months and years, guiding and nurturing us along the way, providing us with great vision and placing on us high expectations. So what comes next? Actions speak louder than words. Let us accept new challenges, think beyond our limits and keep in mind the ethics of life.
Let's undertake everything we can for the sake of unity, humanity and the international community. Let's work together for a more promising future and prosperous world.
1. In the author's eyes, the special ceremony 2020 should| A．be a unique moment to mourn the sacrificed |
| B．be a time to wave a heartfelt goodbye to adversities |
| C．be a moment to open a new chapter of life |
| D．be a glorious time to embrace a beautiful past |
| A．The author came to China so as to escape from wars |
| B．The author witnessed how the original virus spread swiftly |
| C．The author was requested to supply medical aid to the fight against COVID-19 |
| D．Owing to dozens of timely measures,China had a ideal control of the virus |
| A．The strict rules of the government. |
| B．The joint commitment of the nation. |
| C．The harsh circumstance in China. |
| D．The great transformation of the school. |
