Scientists have created a scent(气味)-delivery system that releases a pleasant fragrance when you sweat. Apply it to your skin, and the more you sweat, the better you’ll smell. That’s because the perfume only gets released upon contact with moisture(湿气).
Chemists from Harvard University combined two compounds(化合物) to create their new system. One chemical is alcohol-based. This is the nice-smelling perfume. The other chemical is an ionic liquid(离子性液体), which is a type of salt that is liquid at room temperature. Ionic liquids are made of ions---molecules that have lost or gained one or more electrons. If the molecule loses electrons, it will have a positive charge. If it gains electrons, it gets a negative charge. Ionic liquids contain the same number of positive and negative ions, which makes them neutral(中性的), with no overall electric charge. In general, ionic liquids have no smell.
When the perfume and ionic liquid are mixed together, a chemical reaction occurs. This bonds the molecules to each other. The reaction also temporarily inactivates(使不活跃) the perfume’s molecules. So when applied to the skin, the new perfume has no scent in the beginning. But adding water or sweat breaks the bond between the molecules. That releases the scent into the air.
“The rate of the release of the fragrance depends on how much you sweat, in other words, how much water is available,” explains chemist Nimal Gunaratne from Harvard University, who led the research. “Sweat is like the command to let the fragrance go.”
Christian Quellet is a chemist who has worked in the perfume industry for a long time. He is now an independent consultant based in Switzerland. “Gunaratne’s perfume opens the door to new developments and applications of fragrance controlled-release systems,” he says. Controlled-release systems allow small quantities of some compounds that they hold to enter the environment slowly.
The system also traps some chemicals in sweat that are responsible for the bad sweat smell. These compounds are called thiols (硫醇). Just as water does, thiols break apart the bond that ties the perfume to the ionic liquid. When this happens, the thiols attach to the ionic liquid and their bad scent is inactivated as the perfume had been. This means the water in sweat and its thiols are both able to release the fragrance from the newly developed perfume.
1. Which of the following makes the scent delivery system special?| A．When it releases scent can be well controlled. |
| B．No perfume is required in the system. |
| C．The scent can last for a long time. |
| D．Sweat can help release the scent. |
| A．the perfume comes into contact with the skin |
| B．the perfume and ionic liquid contact each other |
| C．the perfume’s molecules are inactivated by water |
| D．sweat activates the molecules of the perfume in the mixture |
| A．the more you sweat, the better you will smell |
| B．the perfume can’t always cover the bad smell. |
| C．how much water is available doesn’t matter much |
| D．how you smell depends on how much perfume you use |
| A．Indifferent. | B．Favorable. | C．Doubtful. | D．Critical. |
相似题推荐
【推荐1】Too much sitting is bad for you!
Most of us are guilty of excess sitting. We sit at school, at our computers and in front of the TV, moving only to change from one seat to another. Some studies suggest that people who sit all day reduce their life expectancy by around two years compared to those who are more active.
A school in Minnesota decided to experiment with a new ‘standing classroom’ design. They removed the standard desks and replaced them with high tables. These new tables are at chest level and have a swinging footrest.
Other schools are now calculating the costs and benefits of using standing desks. Many are keen to improve their students’ results, and they carefully consider all their performance and attendance data before making a final decision. Parents also need to be consulted as they may have doubts about the effect of these changes on their children. Some schools even organise after-school events where parents, students and teachers can experience a lesson in the newstyle standing classroom.
Dr Khan is unsure how much teenagers can change. He believes that, at that age, they have firmly established habits and they don’t want to do things differently.
| A．They might be reluctant to stand for lessons and they should be allowed to choose whether to stand or sit. |
| B．Today’s teenagers are particularly at risk because of the hours they spend using digital technology. |
| C．Today, schools face a huge challenge to reduce the amount of time students spend sitting. |
| D．As well as the expected health advantages, teachers have noticed other improvements. |
| E．Medical researchers have found evidence that sitting for long periods increases the risk of obesity and diabetes. |
| F．Students are happy with their new environment and especially enjoy the background music, which has been added to improve their learning. |
| G．It is essential that everyone understands the value of these changes as they are expensive to introduce. |
【推荐2】If you’re a pasta (面食) lover, then you know there’re fat noodles, round noodles, shells, and many, many more. Some of these pastas, like ordinary spaghetti, pack easily into small box or package. But others require much larger boxes or bags because of their hard 3D shapes.
Now a team of researchers at Carnegie Mellon University (CMU) and Zhejiang University has figured out a way that pasta can be packed flat, like sticks of gum in a package, and still form fancy 3D shapes once cooked.
Lining Yao who leads the “Morphing Matter Lab” says the team admires flat-pack furniture sold by IKEA that comes tightly packed in a box, but then can be built into a large piece of furniture which takes up a much greater amount of space.
To bring the flat-pack idea to the pasta world, the researchers used computers to help them plan their groove (凹槽) patterns and stamped grooves in the pasta. “The groove side expands less than the smooth side, leading the pasta to change into shape,” explains Teng Zhang, one of the researchers. But knowing where to make them is the trick. By doing that, the researchers are able to fix the shape of the pasta in the end.
Professor Yao has also worked to make noodles fold before, by adding something special that could be eaten to the surface of the pasta. This time, though, the pasta is made with just the right amount of flour and water, and the only things affecting the shape are the grooves.
The new pasta tastes just like ordinary pasta once it is cooked. Meanwhile, this method does not affect the pasta production speed and preservation time. The team hopes their new method will help us in two ways. Like flat-pack furniture, it should take up less space when it’s being transported, which is much easier on the environment. The pasta should also require much less packaging, meaning far less plastic waste.
1. What do we know about pastas from Paragraph 1?| A．They come in different shapes. | B．They are not easy to transport. |
| C．They need to be packed strictly. | D．They are only kept in large boxes. |
| A．The ways of cooking the pasta. | B．The style of gum in a package. |
| C．The furniture design from IKEA. | D．The 3D shapes after it’s cooked. |
| A．By applying the computer apps. | B．By making grooves in right spots. |
| C．By adding the right amount of four. | D．By coating it with something special. |
| A．To produce it more easily. | B．To get it more tasty. |
| C．To keep it longer. | D．To make it greener. |
【推荐3】A robot with a sense of touch may one day feel “pain”, both its own physical pain and sympathy for the pain of its human companions. Such touchy-feely robots are still far off, but advances in robotic touch-sensing are bringing that possibility closer to reality.
Sensors set in soft, artificial skin that can detect both a gentle touch and a painful strike have been hooked up to a robot that can then signal emotions, Asada reported February 15 at the annual meeting of the American Association for the Advancement of Science. This artificial “pain nervous system,” as Asada calls it, may be a small building block for a machine that could ultimately experience pain. Such a feeling might also allow a robot to “sympathize” with a human companion’s suffering.
Asada, an engineer at Osaka University, and his colleagues have designed touch sensors that reliably pick up a range of touches. In a robot system named Affetto, a realistic looking child’s head, these touch and pain signals can be converted to emotional facial expressions.
A touch-sensitive, soft material, as opposed to a rigid metal surface, allows richer interactions between a machine and the world, says neuroscientist Kingson Man of the University of Southern California. Artificial skin “allows the possibility of engagement in truly intelligent ways”.
Such a system, Asada says, might ultimately lead to robots that can recognize the pain of others, a valuable skill for robots designed to help care for people in need, the elderly, for instance.
But there is an important distinction between a robot that responds in a predictable way to a painful strike and a robot that’s able to compute an internal feeling accurately, says Damasio, a neuroscientist also at the University of Southern California. A robot with sensors that can detect touch and pain is “along the lines of having a robot, for example, that smiles when you talk to it,” Damasio says. ‘It’s a device for communication of the machine to a human.” While that’s an interesting development, “it’s not the same thing” as a robot designed to compute some sort of internal experience, he says.
1. What do we know about the “pain nervous system”?| A．It is named Affetto by scientists. | B．It is a set of complicated sensors. |
| C．It is able to signal different emotions. | D．It combines sensors and artificial skin. |
| A．Delivered. | B．Translated. | C．Attached. | D．Adapted. |
| A．Robots can smile when talked to. |
| B．Robots can talk to human beings. |
| C．Robots can compute internal feelings |
| D．Robots can detect pains and respond accordingly. |
| A．Machines Become Emotional | B．Robots Inch to Feeling Pain |
| C．Human Feelings Can Be Felt | D．New Devices Touch Your Heart |
【推荐1】We can video chat with astronauts aboard the International Space Station and watch live footage from the frozen heights of Everest. But communicating with a submarine (潜艇) or a diver is not so easy. The lack of practical methods for sharing data between underwater and airborne devices has long been a frustration for scientists. The difficulty stems from the fact that radio signals work perfectly in air travel but poorly in water. Sonar(声呐)signals used by underwater sensors reflect off the surface of the water rather than reaching the air.
Now, researchers at MIT have developed a method with the potential to revolutionize underwater communication. "What we've shown is that it's actually feasible to communicate from underwater to the air，" says Fadel Adib, a professor at MJT's Media Lab, who led the research.
The MIT researchers designed a system that uses an underwater machine to send sonar signals to the surface, making vibrations (震动)corresponding to the Is and Os of the data. A surface receiver then reads and decodes these tiny vibrations. The researchers call the system TARF. It has any number of potential real-world uses, Adib says. It could be used to find downed planes underwater by reading signals from sonar devices in a plane' s black box and it could allow submarines to communicate with the surface.
Right now the technology is low-resolution. The initial study was conducted in the MIT swimming pool at maximum depths of around 11 or 12 feet. The next steps for the researchers are to see if TARF is workable at much greater depths and under varying conditions-high waves, storms, schools of fish. They also want to see if they can make the technology work in the other direction- air to water.
If the technology proves successful in real-world conditions, expect "texting while diving" to be the latest underwater fashion.
1. What does the author mainly talk about in Paragraph 1？| A．The future of video chat underwater and in air. |
| B．The difficulty of communication from water to air. |
| C．The frustrations of developing underwater devices. |
| D．The current situation of communicating with a submarine. |
| A．Changeable. | B．Convenient. | C．Achievable. | D．Alternative. |
| A．It is widely used to find downed planes. |
| B．It can work well at great depths underwater. |
| C．It is an underwater machine that sends signals. |
| D．It can send, receive and read signals from underwater. |
| A．The Real-world Uses of Sonar Technology |
| B．A Breakthrough in the Application of Video Chat |
| C．Full Water-to-air Communication Closer to Reality |
| D．TARF Becoming a New Means of Communication |
【推荐2】In July 1915, sick James Murray, one of the early editors of the Oxford English Dictionary (OED), defined one final word. He had devoted 36 years to the dictionary. Knowing he would not see the project complete, he wrote his last entry: for “twilight”.
The story of Murray’s final days is one of many memorable tales in “The Dictionary People”. Conceived (构思) in 1857, the OED was a huge crowdsourcing project comprising 3,000 people. The idea was to create a “descriptive” dictionary that tracked words’ use and meaning over time. Volunteers read widely, mailing in examples of how “rare, old-fashioned, new” words were used. What is surprising about this random method is that it worked, achieving order through the large number of contributors.
The origin story of Sarah Ogilvie’s book is almost as improbable as that of the dictionary itself. Ms Ogilvie, an editor for the OED, went into the archives (档案馆) of Oxford University Press and came across an old notebook. It had belonged to Murray and contained the names and details of the dictionary volunteers, most of whom had previously been unknown. “The Dictionary People” is her work of detective scholarship, presenting the lives behind the names.
The dictionary’s contributors are an engaging cast, including one of Karl Marx’s daughters and J. R. R. Tolkien. For some, the dictionary was something addictive: one contributor supplied 165,061 quotations. Murray, too, was assiduous. He once wrote to George Eliot to ask about a word choice in “Romola”, published 17 years earlier.
Ms Ogilvie’s book is full of strange but interesting tales. Many dictionary lovers engaged in another crowdsourcing fashion: collecting and measuring rainwater. The presentation of the book is irregular, too, taking its structure from the work it describes. For example, in her first chapter, “A for Archaeologist (考古学家),” she relates the early life of Margaret A. Murray, a pioneering Egyptologist. There are 26 alphabetical (按字母顺序排列的) chapters, each celebrating a group of contributors. This is a clever concept.
1. What did the OED’s volunteers do?| A．They deleted the words going out of use. |
| B．They listed instances of changes in word use. |
| C．They corrected the misuse of common words. |
| D．They added new words to keep up with the times. |
| A．What Ogilvie achieved with it. | B．How Ogilvie told the stories in it. |
| C．What inspired Ogilvie to write it. | D．Who helped Ogilvie to complete it. |
| A．Hard-working. | B．Easy-going. | C．Energetic. | D．Flexible. |
| A．Interesting and creative. | B．Encouraging and influential. |
| C．Traditional and funny. | D．Descriptive and surprising. |
【推荐3】Scientists have not found any signs of life on Mars yet,but they say a robotic vehicle called “Curiosity” is helping them learn a lot about the planet’s history and climate.
Curiosity landed on Mars in August 2012 after travelling through space for more than eight months.It was sent to Mars by scientists from NASA in the United States.
Curiosity is about the size of a car and has six wheels.It also has a robotic arm,cameras,and instruments that allow it to examine things it finds on the surface.Then it sends the information back to the earth.
Curiosity’s main task is to find out if anything could live on Mars,either now or in the past.On Nov.2,NASA scientists held a press conference (新闻发布会) to discuss what Curiosity had found in its first two months on Mars.
Curiosity has found soil that is similar to the sand formed by volcanoes (火山) on the earth.Scientists say that studying the minerals in Martian soil will help them understand what conditions were like on the planet in the past.Curiosity also found smooth stones like the ones found on river beds and seashores on the earth,where their rough edges have been worn down by water.Mars is very cold and dry now,but scientists say the smooth stones tell them that a river used to run through the place where they were found.
Curiosity has been testing the atmosphere around Mars for a type of gas called methane (甲烷),but so far it has not found any.On the earth,most methane is produced by plants or animals.Methane on Mars might indicate that some type of tiny plants or animals lived there.
Curiosity is the fourth robotic vehicle to be sent to Mars.It will continue to explore the planet for about two years.
1. Which of the following descriptions about Curiosity is TRUE?| A．It landed on Mars in January 2012. |
| B．It is small in size and has four arms. |
| C．It took over eight months to arrive in Mars. |
| D．It was sent to Mars by scientists from Russia. |
| A．there’s no air on Mars | B．Mars is warm and wet now |
| C．the soil on Mars is rich | D．there used to be water on Mars |
| A．smooth stones | B．rivers |
| C．robotic vehicles | D．volcanoes |
| A．some tiny animals once lived on Mars |
| B．there are no plants or animals on Mars now |
| C．the atmosphere around Mars is full of methane |
| D．Curiosity is designed to test the atmosphere around the earth |
| A．Humans benefit a lot by going to Mars. |
| B．Scientists will stop the research on Mars soon. |
| C．It is possible to build an earth-like environment on Mars. |
| D．A robotic vehicle helps scientists get useful information from Mars. |
【推荐1】Alongside air and water, food is a necessity (必需) for human beings to survive and thrive (蓬勃发展). But it’s a lot more than that. As Mariette DiChristina of Scientific American wrote: “The most intimate (亲密的) relationship we will ever have is not with any fellow human being. Instead, it is between our bodies and our food.”
Nowadays, for most people in the world’s wealthiest countries, food is a hobby, an enthusiasm, and even something fashionable.
Turn on the TV in the US, UK or France, and you’ll find at least one channel feeding this popular obsession (迷恋).
And most of us know at least one person who thinks of themselves as a “foodie”. It’s almost impossible nowadays to check our social media apps without at least two or three photos of delicious meals appearing on our screen － however annoying we may find it.
But behind the fancy recipes and social media bragging (夸耀), many of us forget how much we take food for granted.
This is why World Food Day is held each year by the United Nations on Oct 16. The day allows the UN’s Food and Agriculture Organization to highlight (强调) both the progress that has been made against hunger, and the awful amount of progress that still needs to be made.
Take Kenya for example. This East African nation has been suffering terrible droughts, some of the worst in recent years. The result is that people are beginning to starve. Children in particular are suffering, with some of them even dying.
This may seem shocking to know, especially as many cultures outside of Africa think of food in a completely different way. But even in developed nations in the West, families on low incomes (收入) are forced to use food banks － organizations that hand out donated (捐赠) food to those who can’t afford to pay for it themselves.
So what can we do on World Food Day? One good way to spend it would be to feel humble and appreciate what we have. After all, food is essential for our survival, but not everyone is as lucky as we are when it comes to dinner time.
1. The author borrowed Mariette DiChristina’s words to ______.| A．discuss the latest trend in the food industry |
| B．point out the food shortage problem in the world |
| C．emphasize the connection between food and humanity |
| D．show the importance of food for human survival |
| A．have turned many people into foodies |
| B．are very popular among viewers |
| C．will soon be replaced by social media apps |
| D．often mislead people’s opinion of food issues |
| A．raise awareness of the issues behind hunger |
| B．share fancy recipes and promote food cultures |
| C．call on people to donate food to those in need |
| D．inform people of the food crisis in Africa |
| A．give more food to charity | B．share food with their neighbors |
| C．feel grateful for the food they eat | D．skip meals sometimes to save food |
【推荐2】The driver who cuts you off in traffic.The neighbors who don't pick up after their dog.Situations such as these get our hearts racing and send our stress levels skyrocketing.Anger isn't a pleasant feeling.Some of us bottle up the emotion, while others explode in a wild rage (狂怒).Both habits do considerable harm to our bodies, our minds, and our relationships.
“Anger may fee1 uncomfortable and a lot of people think they have to get rid of their anger," says Patrick Keelan, a registered psychologist in Calgary, Alberta.“But anger is an emotion built into us to signal that something needs to be addressed.When we take notice of that signal and actually wrestle with the problem instead of turning a blind eye to it, we' re usually much better for it.”
Unfortunately, many of us have been conditioned to keep our emotions hidden.Increasingly,research is suggesting that this can have long-term effects on our health.Investigators at the University of Rochester noticed that people who contain their emotions tend to live shorter lives.When we're angry, stress hormones are released, which can make us more likely to develop a wide range of diseases, including diabetes, depression, immune related conditions.
Is it better, then, to scream and howl whenever something makes you mad? That's probably the reason why“rage rooms" have popped up in many American cities, where folks are invited to let steam off by violently smashing (打碎) stuff in a“safe" environment.However, the research indicates that when people display anger aggressively, it can actually increase the intensity of the anger -- and increase the likelihood of aggressive actions in the future.It doesn't take much imagination to predict how such behavior can affect your relationship with your spouse, your kids, or your colleagues.It also hurts your health.A large 2016 study at McMaster University found that people are more than twice as likely to have a heart attack after an angry explosion.
If we shouldn't bottle up our angry feelings but aggressive behavior isn't healthy either, how should we handle things that tick us of? It's the extreme highs and lows that cause the damage.If you're able to apply techniques that smooth out some of those peaks and valleys, you can have a gentler ride.
1. What does the underlined phrase“bottle up" in paragraph 1 mean?| A．Build up. |
| B．Hold back. |
| C．Let off. |
| D．Bring out. |
| A．Uncomfortable and avoidable. |
| B．Terrible and threatening. |
| C．Confusing and complex. |
| D．Normal and natural. |
| A．It leads to people's depression. |
| B．It warns people against violence. |
| C．It adds to people's anger. |
| D．It helps people to calm down. |
| A．Possible causes of anger. |
| B．Tips on handling anger. |
| C．Possible harm of anger. |
| D．Tips on avoiding anger. |
【推荐3】It is common for adults to use ''baby talk'' when interacting with babies. This way of speaking attempts to imitate the sounds babies make when they first try to talk. But is this form of communication helpful to a child’s development?
Several studies have suggested a clear link between parental language methods and a child's early language development. Studies showed that language learning in babies was improved when parents spoke more than a few simple words and used a wider vocabulary. Earlier research found that the style of speech used by parents to communicate with their baby could have an influence on language development.
One such speaking style is known as ''parentese''. Research has shown that babies react better to this kind of language in the first months of life. Generally, parentese involves adults speaking in a higher voice and at a slower speed. The language is simplified, while sentences are short and often repeated. Studies from the past 30 years have confirmed that babies spoken to in parentese developed larger vocabularies throughout the first three years of life.
A new study on the subject, a project of the University of Washington's Institute for Learning & Brain Sciences, examined whether parents can be effectively taught methods to improve their parentese skills.
Naj a Ferjan Ramírez. working in the Institute for Learning＆Brain Sciences, said that the parents involved in the research were first shown the importance of language input for their baby's development. Parents were then given suggestions on how to use different parentese methods, and then rated on how well they used these methods with their child. She added that the new study is important because there are still a 1ot of parents with little knowledge about how to use parentese to help their child. This was one reason the researchers included parents from different cultural and economic groupings.
1. How do parents usually talk with their babies?| A．By speaking in a funny style. | B．By copying babies' sounds. |
| C．By raising speaking speed. | D．By whispering in babies’ears. |
| A．Babies' language skills are decided by talent. |
| B．Babies' language is improved by simple words. |
| C．Parental language style helps improve babies' behavior. |
| D．Parental language methods affect babies' language development. |
| A．In paragraph 2. | B．In paragraph 3. |
| C．In paragraph 4. | D．In paragraph 5. |
| A．Communicating with babies matters more |
| B．Parentese is a good way to practice language |
| C．The more parents help, the better babies 1earn |
| D．Speaking parentese helps with babies' language learning |
【推荐1】Young sunflowers turn and swing every day. New findings add to evidence that the plants are animal-like.
Harmer, a professor in the University of California at Davis’ Department of Plant Biology, carried out a series of experiments on sunflowers in the field, in pots outdoors and in indoor growth chambers.
By staking plants so that they could not move, Harmer showed that he could destroy their ability to track the sun. He also noticed that sunflowers prevented from moving were not as tough and leafy as those that were free to move. When plants were moved indoor with a settled overhead light, they continued to swing back and forth for a few days.
The indoor plants did start tracking the “sun” again when the apparent source of lighting was moved across the room. The plants could reliably track the movement and return at night when the artificial day was close to a 24-hour cycle, but not when it was closer to 30 hours.
When sunflowers track the sun, the cast sides of their stems grew more rapidly than the west sides. Ai night, the west sides grew faster as the stem swung the other way. The team identified a number of genes that were expressed at higher levels on the sunward side of the plant during the day, or on the other side at night. A plant growth-regulating hormone, called auxin, appears to be a key driver.
The “dance” to the sun cycle obviously slows when the sunflower matures and its flowers open up. At that point, the plants stop moving during the day and settle down facing the sun in the east.
“Bees like warm flowers.” Harmer said, adding that the bees are cold-blooded, so landing on a warm flower saves them energy and perhaps feels really good.
“The morning warmth changes the flowers in a way to make them more appealing to insects, perhaps causing them to release more attractive scents earlier in the day.” he said. “We’re currently testing this idea.”
1. Why did Harmer do the experiment on sunflowers?| A．To see how sunflowers grow up. |
| B．To show what sunflowers’ genes are. |
| C．To study why sunflowers track the sun. |
| D．To check if sunflowers swing in cloudy days. |
| A．Tracking. | B．Fastening. |
| C．Preserving. | D．Researching. |
| A．They won’t grow well. |
| B．They will grow faster than usual. |
| C．They won’t swing back though set free. |
| D．They will produce a number of new genes. |
| A．They attract more insects. | B．They save more energy. |
| C．They mature more rapidly. | D．They produce more flowers. |
【推荐2】Like most people living in the suburb, Janice Monkowski, who lives some 30 miles east of San Francisco, gets around mainly by car. For much of her life, public transportation was not even an afterthought. That changed recently when Monkowski, a self﹣described technophobe(技术恐惧者), discovered Moovit. When she goes to San Francisco to meet friends, the smart- phone app let her plan bus and train trips down to the minute. “Moovit tells me where to walk and how long it might take to catch a bus to get to the train station,” Monkowski says.
Much like the navigation app Waze, which follows its users on the road to determine the best driving routes， Moovit collects location data of nearby users to show how to travel along the way with less time and energy between two locations. Nir Erez who cofounded Moovit says, “Most commuters(每天长途上班的人) don’t know when a bus might arrive, let alone how it might connect with another transit service, or when walking or bicycling might be faster.”
In just several years Moovit has had 100 million users. Moovit is available in 44 languages and 82 countries, and commuters in more than 2,500 cities rely on it to get to and from work. In 2016 Moovit became the official transit app for the Summer Olympics in Rio de Janeiro. In 2018, Moovit was also chosen as the official mobility app of the Asian Games. When public transit doesn’t get a user all the way to where they want to go, Moovit may connect her to bike﹣share programs or services like Uber.
As Moovit has grown to 100 employees, with headquarters(总部) near Tel Aviv and offices in big cities such as San Francisco, Athens and Rio, Moovit can provide better, more up﹣to﹣date information at a lower cost. Best of all: It’s all built one data point at a time by people like Monkowski. When you go to San Francisco and don't want to drive before the city’s “terrible” parking and traffic, Moovit can give you another option. It’s very simple.
1. How does Moovit help Janice Monkowski?| A．By helping her have a comfortable trip. |
| B．By helping her learn advanced technology. |
| C．By helping her balance her tight travel budget. |
| D．By helping her arrive at where she wants to go. |
| A．It provides more good services. |
| B．It involves more simple orders. |
| C．It predicts the most efficient trip. |
| D．It stores more available information. |
| A．The exact location of Moovit. |
| B．The bright future of Moovit. |
| C．The development of big cities. |
| D．Some special opinions on public transportation. |
| A．The wide use of Moovit |
| B．The unique development of Moovit |
| C．The quick development of Moovit |
| D．The obvious advantage of Moovit |
【推荐3】A crucial period for learning the rules and structure of a language lasts up to around age 17 or 18, say psychologist Joshua Hartshorne of MIT and his colleagues.
Previous research had suggested that grammar-learning ability developed in early childhood before hitting a dead end around age 5. However, Hartshorne’s team reports online in Cognition that people who started learning English as a second language in an English-speaking country by age 10 to 12 ultimately mastered the new tongue as well as folks who had learned English and another language at the same time from birth. Both groups, however, fell somewhat short of the grammatical fluency displayed by English-only speakers. After ages 10 to 12, new-to-English learners reached lower levels of fluency than those who started learning English at younger ages because time ran out when their grammar-absorbing ability fell starting around age 17.
Aiming for a sample of tens of thousands of volunteers, Hartshorne began by contacting friends on Facebook to take an online English grammar quiz, which used a person’s responses to guess his or her native language and dialect (方言) of English. Then volunteers filled out a questionnaire asking where they had lived, languages they had spoken from birth, the age at which they began learning English and the number of years they had lived in an English-speaking country.
In the end, the researchers analyzed responses of 669,498 native and nonnative English speakers. Statistical calculations focused on estimating at what ages people with varying amounts of experience peaking English reached peak grammar ability.
Researchers who study language learning regard the new study as fascinating, but exploratory. According to psycholinguist David Barner of the University of California, San Diego, Hartshorne’s team can’t yet say that language skill develops along a single timeline. Different elements of grammar, such as using correct word order or subjects and verbs that agree with one another, might be learned at different rates, Barner says. It’s also unclear whether the responses of volunteers to an online, 132-item grammar test reflect how well of poorly they actually speak English, he says.
What’s more, language learning involves more than a crucial period for acquiring grammar, cautions linguist David Birdsong of the University of Texas at Austin. For instance, growing up speaking two languages at once puts still poorly understood burdens on the ability to grasp grammar, he says.
In the new study, people who were bilinguals from birth fell short of peak English grammar scores achieved by English-only speakers. That’s consistent with evidence that bilinguals cannot easily turn off one language while speaking another, Birdsong says. Interactions between tongues spoken by one person may slightly depress how much can be learned about both languages, even if bilingual communication still reaches high levels, he suggests.
1. Hartshorne and his colleagues found that____ .| A．one reaches a higher level of fluency at age 10 |
| B．one learns a second language fastest at about age 12 |
| C．one gets a good grasp of English grammar before age 5 |
| D．one’s ability to master grammar declines at around age17 |
| A．social media |
| B．experiments in the lab |
| C．literature review |
| D．face-to-face interviews |
| A．language skill develops along a single timeline |
| B．online volunteers do not cover a wide enough range |
| C．different grammar items may be acquired at different paces |
| D．the quiz in the new study does not include enough questions |
| A．They can achieve a perfect grammar score. |
| B．Grammar learning is the biggest burden for them. |
| C．They are able to make a swift shift between languages. |
| D．Speaking two languages affects their language acquisition. |
