1 . Someday, you may no longer need to brush your teeth by hand. Instead, a group of billions of nanoparticles (纳米粒子) could automatically do it for you. It would be especially life-changing for those who find it difficult or impossible to hold and move a toothbrush.
Steager, an engineer at the University of Pennsylvania in Philadelphia and Hyun Koo, an inventor and dental researcher there, found a way to form the nanoparticles into long, skinny bristles (刷毛), a lot like the ones on a toothbrush. But these bristles shape-shift to fit whatever surface they encounter.
The tooth-cleaning robot works due to two magnets (磁铁). One goes each side of the teeth. The nanoparticles sit in a liquid between the magnets. When the magnets are turned off, the nanoparticles move randomly in the liquid. As soon as one magnet gets turned on, the nanoparticles gather together near its center. When the researchers turn on the other magnet and turn off the first one, the nanoparticles extend outward in long, skinny bristles. When there’s a tooth in the way, these bristles can’t stretch out as far as they want. So they push against the tooth’s surface. If there’s a gap between teeth, they push into the gap. Moving the magnets makes the bristles move against and between teeth. All that motion cleans the teeth. As a bonus, the nanoparticles also have strong power to kill viruses.
The new device is just a proof of concept. The researchers still need to turn it into a product that people will want to use. “There’s a lot of engineering to get from here to there, but every good idea needs to have a start.” says Steager.
1. What is special about the tooth cleaner?A.It’s transformable. | B.It’s water-proof. |
C.It contains skinny bristles. | D.It looks like a toothbrush. |
A.The working principle. | B.The magnets’ motion. |
C.The virus-killing process. | D.The bristles’ formation. |
A.Uncertain. |
B.Concerned. |
C.Confident. |
D.Shocked. |
A.A Tooth-Cleaner Fighting Bacteria | B.A New Concept for a New Start |
C.A Breakthrough in Medicine | D.A Shape-Shifting Robotic Tooth-Gleaner |
2 . The Forbidden City is well known for being full of Chinese cultural and historical relics. But Masters in the Forbidden City(《我在故宫修文物》)does not just focus on the stories of the past.
Instead, the documentary movie, which came out in Chinese cinemas on Dec. 16, focuses on ordinary people-the restorers(修复者)of relics and antiquities(古董).
The stories are told at a slow and relaxed pace, reflecting the restorers’ work. Restoration of cultural relics and antiques can be time-consuming, and sometimes boring. Yet these restorers’ patience and peace of mind are especially precious in a society where everything is changing so fast.
“If you choose this job, you have to stand hours of work sitting on a chair. You need to be quiet and get used to being quiet,” says Wang Jin, an ancient clock repair expert.
A touching part of the documentary is the spirit of craftsmanship(工艺)in the restorers. “Years of humdrum work requires not only skill, but also faith and spirit,” China Daily commented. “Looking for preciseness and perfection, devoting yourself to work, patience, endurance(忍耐), loneliness…All these qualities come from the craftsman spirit. ”
But unlike the popular idea of serious experts who sit around being serious, the documentary shows off the enthusiasm of the restorers. They play their guitars and make jokes about each other after a long day of restoration work.
One scene that has been very popular with Internet users features a young female restorer riding a bicycle through the empty Forbidden City on a Monday. While she is doing this, a narrator says, “The last person to do this was Puyi, the last emperor of the Oing Dynasty.”
Masters in the Forbidden City has proved wrong many people’s ideas about antique restorers, allowing them to realize that they are not old, dull professors, but people in their 40s, 30s and even 20s who can be quite pleasing to the eye.
1. According to the text, what’s the main purpose of the documentary Masters in the Forbidden City?A.To show people how antiques are restored |
B.To display relics seldom seen by ordinary people |
C.To draw attention to Chinese antique restorers’ lives |
D.To praise the craftsmanship of Chinese antique restorers |
A.He often gets tired with his work | B.There is no need to do restoration work fast |
C.Antique restorers need to be patient and peaceful | D.It takes years of hard work to adapt to antique restoration |
A.Boring | B.Different | C.Relaxing | D.Unusual |
A.To remind the audience of the last Qing emperor |
B.To show the strange hobbies of young antique restorers |
C.To encourage the young to consider a career in antique restoration in the future |
D.To show that the documentary breaks from the old, dull image of antique restorers |
Louis Pasteur was a French scientist who developed cures for many dangerous
Pasteur was born in 1822, in Dole, France. He was a courageous student who
In the 1870s, Louis Pasteur sought to find a cure for anthrax—a disease
Pasteur died in 1895, in Saint-Cloud, France. On his last day he remarked: "I should like to be younger, so as to devote myself
增加:在缺词处加一个漏字符号(^),并在其下面写出该加的词。
删除:把多余的词用斜线(\)划掉。
修改:在错的词下划一横线,并在该词下面写出修改后的词。
注意:1. 每处错误及其修改均仅限一词;
2. 只允许修改10处,多者(从第11处起)不计分。
Dear Chris,
I am glad to hear you are interested on Double 11. Now let me to tell you something about them. Double 11 has become a special day in recently years. With four "1"s, it is also called Singles' Day. On that day, single young people held parties to show love or simply have funs. In 2009, Double Eleven Shopping Day was held to promoting online shopping, that has become the biggest online shopping day in China now.
In my view, this day is chance of promoting business. People should make purchases wisely. What do you think of this day? Look forward to your opinion.
Yours,
Li Hua
5 . One rainy afternoon, I was on a crosstown bus when a young woman jumped on. She had a child with her who was about three or four years old. The bus was full, bumpy(颠簸的), and it soon got noisy, as her kid began crying — he was upset that he couldn't sit next to his mother. She looked embarrassed.
Then another woman, a little older, stood up and moved so that the mother and child could sit together. The mum smiled as a thank-you. And then three words came out of the older woman's mouth that raised the entire energy of that bus ride: “I've been there.”
Simple, undramatic, and honest. In that moment, it seemed to unite the diverse people of the city. Why? Because almost all experiences are shared human experiences. They're universal. We forget that as we go through life, focused on our own troubles and needs — which are actually less unique than we think.
Sometimes painful past experiences prevent us from wanting to open up to others because we don't want to revisit our own history. But a wonderful way to honor your past hurt is to help comfort another's current pain.
When I was a little girl, we lived on donations from local families and clothing from the " lost and found" baskets. It was shameful for me at the time — I lived in fear of being caught in a friend' s cast-off item.
Even when it was warmer, I refused to take off a layer in the classroom for this reason. Now I don't meet people who are in this exact situation, but I do notice when someone is struggling with financial shame or feels less than other people they meet. And I'm quick to say some version of, "I've been there."
Can the essence of these three words help you make a small difference right now? It can be as simple as volunteering your seat, sharing some helpful advice, or even lightening the mood with a joke when you notice that someone's uncomfortable — because we're all in this together.
1. What influence did the older woman's words have on the people around?A.Causing discomfort. | B.Breaking long silence. |
C.Creating a heated debate. | D.Inspiring common feelings. |
A.They are mostly shared experiences. | B.They don't really matter to anyone' |
C.They will be forgotten with time. | D.They are unique to each individual. |
A.Because she had the same sweater with others. |
B.Because she stole the sweater from someone' |
C.Because she liked wearing the coat in summer. |
D.Because she felt embarrassed wearing others' clothes. |
A.Painful Experiences Are No Big Deal | B.The Best Way to Honor Your Past Hurt |
C.True Happiness Comes from Helping Others | D.Three Little Words That Bring Us Together |
6 . What do extreme marathoners, mountain hikers and professional bicycle racers all have in common? They push their bodies to unsustainable (不可持续的) extremes of physical stress.
We tend to think there’s no limit to human physical achievements. But a new study, published in Science Advances, says there is a definite limit to human endurance (耐力). Beyond that, our bodies begin to break down.
To find the limit, a US research team tracked marathon runners over a five-month period, measuring competitors’ initial basal metabolic rates (BMR, 基础新陈代谢率) – the amount of energy they expend when they rest. Then they looked at how many calories(卡路里) each runner burned per day.
The team found that the maximum amount of energy a human can expend is 2.5 times of BMR. It equals 4,000 calories of energy per day. These calories can help a trained athlete to run about 42 kilometers in a day.
But people can’t keep using this amount of calories all the time. “You can do really intense stuff for a couple of days, but if you want to last longer then you have to dial it back,” US evolutionary anthropologist Herman Pontzer told the BBC.
Pontzer explained that the problem is our guts (消化道). “There’s … a limit to how many calories our guts can effectively absorb per day,” he said in the Daily Mail. At that point, the body is burning calories more quickly than it can absorb food and convert (转化) it into energy.
These new findings could help athletes to best work underneath this ceiling. For example, they could manage their daily exercise time based on their BMR, to get enough calories and keep going.
However, Pontzer’s team can’t rule out the possibility of someone breaking this limit. “So I guess it’s a challenge to elite endurance athletes,” said Pontzer. “Science works when you’re proven wrong. Maybe someone will break through that ceiling some day and show us what we’re missing.”
1. What did the US research team find in the new study?A.One’s endurance can be improved through exercise. |
B.A trained athlete can do intense activities for more than a week. |
C.The average BMR for athletes is 4,000 calories of energy per day. |
D.The energy one can expend is no more than 2.5 times of their BMR per day. |
A.To tell us the problem with our guts. |
B.To show how our bodies produce energy. |
C.To explain why there is a limit to human endurance. |
D.To prove the importance of our guts to physical activities. |
A.keep a more balanced diet |
B.save time and reduce stress |
C.arrange their training properly |
D.improve their performance quickly |
A.It’s possible that someone could break the endurance limit. |
B.It’s no good trying to work above the 2.5x endurance ceiling. |
C.Further data is needed to make the study’s results more accurate. |
D.The 2.5x endurance ceiling is not a problem for many elite athletes. |
7 . Greenberg was a lucky guy to enter Columbia University on full scholarship. But just before junior year, Greenberg's
As Greenberg' s best friend, Arthur persuaded Greenberg to go back to Columbia and
Then, one afternoon, Greenberg and Arthur went to Midtown Manhattan. When it was time to go back to campus, Arthur said he couldn’t
Greenberg, who was completely
At the university's gates, someone
Blindness doesn't make Greenberg fail to appreciate the
A.faith | B.attitude | C.fortune | D.reputation |
A.lit | B.cleared | C.steamed | D.cheered |
A.However | B.Moreover | C.Therefore | D.Otherwise |
A.shy | B.selfish | C.desperate | D.nervous |
A.learned | B.pretended | C.happened | D.offered |
A.letters | B.textbooks | C.newspapers | D.magazines |
A.imagined | B.ended up | C.carried on | D.considered |
A.tentative | B.confident | C.excited | D.curious |
A.accompany | B.rescue | C.comfort | D.abandon |
A.explained | B.apologized | C.compromised | D.panicked |
A.consulting | B.finding | C.leaving | D.serving |
A.tired | B.amused | C.satisfied | D.confused |
A.got off | B.pulled over | C.looked around | D.ran away |
A.turned to | B.knocked into | C.shouted at | D.quarreled with |
A.raised | B.lost | C.controlled | D.recognized |
A.pleasure | B.anger | C.relief | D.sorrow |
A.achieved | B.questioned | C.ignored | D.missed |
A.Gradually | B.Finally | C.Obviously | D.Strangely |
A.complex | B.familiar | C.defensive | D.brilliant |
A.magic | B.truth | C.wisdom | D.beauty |