Diseases spread in many ways. An infected person can cough or sneeze on someone nearby, or they can spread germs through a handshake. But sometimes we pick up germs indirectly. A sick person might leave behind bacteria or viruses when they touch a door handle, for example. But what if those surfaces could clean themselves?
Two teenagers from Hong Kong asked themselves the same question. Now they’ve developed a door handle that can kill germs on contact. The idea is simple. Every time the door is opened, the movement creates power that starts a germ-killing reaction on the handle. In lab tests, their system killed about 99.8 percent of the germs that they spread onto lab dishes covered with their material.
Research by others has shown that door handles in public areas are often home to lots of bacteria and viruses, notes 17-year-old Sum Ming (Simon) Wong. He and schoolmate Kin Pong (Michael) Li, 18, wanted to design a covering for door handles that would kill germs. After doing some research, they learned that a mineral called titanium dioxide (二氧化钛) is known to kill bacteria. It’s already used in many products, from paints to desserts. To make their covering, the teenagers made the mineral into a very fine powder.
Titanium dioxide kills bacteria best when lit by ultraviolet (紫外线的) light, says Simon. UV light is found in sunlight. But UV light does not naturally shine on indoor handles or any used at night, so the teenagers light their door handle from within. To make sure the light reaches the coated surface, the teenagers made their door handle out of clear glass. Each end fits into a bracket (托架). Inside one of the brackets is a strong light-emitting diode (LED). From it comes UV light. And here’s the interesting and praisable part: The power that makes the UV light shine comes from opening and closing the door. The power from the door is then carried by wire to the LED inside the door handle.
The door handle system, Michael and Simon say, might cost no more than about $13 (about 81 yuan) to build.
1. Why does the author mention the ways diseases spread at the beginning?| A．To explain how to kill bacteria or viruses effectively. |
| B．To demonstrate how most diseases are spread indirectly. |
| C．To remind readers of the importance of cleaning their hands. |
| D．To help to describe a new invention that prevents diseases from spreading. |
| A．It is too expensive for ordinary families. | B．It is powered by the movement. |
| C．It works better at night than daytime. | D．It is made of a metal absorbing UV light. |
| A．By producing titanium dioxide to kill bacteria. |
| B．By supplying enough power to the handle system. |
| C．By directing the UV light in sunlight to the coated surface. |
| D．By providing UV light to help titanium dioxide work better. |
| A．Cautious. | B．Critical. | C．Enthusiastic. | D．Disappointed. |
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【推荐1】It is nothing new that most of us know that physical activities lead to better health. But for the first time in these years, the United States government has changed its guidance on how much exercise people need to stay healthy and when they should start.
The new guidance states that children as young as three need to be physically active. Earlier guidelines used to begin at six. The most important time for children to begin exercising is between the ages of three and five. Boys and girls in this age group need at least three hours of exercise every day. That could be light activities, moderate (中等的) activities, or even strong activities.
Doctors say it is important to start at a young age. They add that from birth to the age of five, a child's brain develops more than at any other time in life. These developments have a lasting influence on a child's ability to learn and to succeed in school and in life. Children who start exercising at a young age are more likely to develop healthy behavior that will continue into adulthood. However, Dr. Giroir, who works at the U.S. Department of Health and Human Services, does not suggest putting a five-year-old child on a "treadmill (跑步机)"or other exercise equipment. He thinks that simply giving children the time and space to play actively as they normally would is enough.
The new guidelines say that children aged between 6 and 17 get at least one hour of moderate to strong exercise a day. Most of this exercise should be aerobic exercise (有氧运动)，such as biking, swimming or running. Aerobic activities can strengthen (加强)the heart and lungs by making them work hard for several minutes or more. Exercise should also include muscle- and bone-strengthening activities, such as climbing trees or playing sports. Experts suggest that children get this kind of exercise at least three times a week.
1. What's the best age to begin exercising?| A．Under three. |
| B．Above six. |
| C．Between three and five. |
| D．Between six and seventeen. |
| A．run on the treadmill every day |
| B．do aerobic exercise regularly |
| C．be given more free time to play |
| D．do muscle-strengthening activities |
| A．His heart and lungs will be stronger. |
| B．His brain will develop faster. |
| C．He will be big-boned. |
| D．He will grow higher. |
| A．The earlier exercise guidance is given, the better |
| B．New exercise instruction: Start earlier |
| C．Children need more exercise |
| D．Life lies in movement. |
【推荐2】The bad health effects of sleep loss during the week can’t be repaid by longer weekend sleep, according to a new study.
Researchers have long known that sleep deprivation (剥夺) can cause weight gain and increase other health risks. But for those who force themselves out of bed every weekday after too few hours of shut-eye, they hope turning off the alarm on Saturday and Sunday will repay the weekly sleep debt and remove any ill effects.
The research, published in Current Biology, crushes those hopes. Despite complete freedom to sleep during a weekend recovery period, people in a sleep lab who were limited to five hours of sleep on weekdays gained nearly three pounds over two weeks and experienced disorders that would increase their risk for diabetes over the long term. While weekend recovery sleep had some benefits after a single week of sleep loss, those gains were wiped out when people fell right back into their same sleep-deprived schedule the next Monday.
“If there are benefits of catch-up sleep, they’re gone when you go back to your daily schedule. It’s very short-lived,” said Kenneth Wright, director of the sleep and chronobiology lab at the University of Colorado at boulder. “These health effects are long-term. It’s kind of like smoking once was—people would smoke and wouldn’t see an immediate effect on their health, but people will say now that smoking is not a healthy lifestyle choice. I think sleep is in the early stage of where smoking used to be.”
Wright said that the study suggests people should put sleep in the first place—cutting out the “sleep stealers” such as watching television shows or spending time on their phones. Even when people don’t have a choice about losing sleep because of child-care responsibilities or job schedules, they should think about getting sleep in the same way they would get a healthy diet or exercise.
1. What do the researchers find about weekend recovery sleep?| A．It is common among people. |
| B．It will make people healthier. |
| C．It can make people put on weight. |
| D．It’s able to make up for the sleep loss. |
| A．Arouses. | B．Guarantees. |
| C．Deepens. | D．Ruins. |
| A．It takes long for people to see the effects of sleep loss. |
| B．Smoking and sleep loss have the same bad effects. |
| C．Weekend recovery sleep has many benefits. |
| D．Smoking is more harmful than sleep loss. |
| A．Sleep as long as possible during weekdays. |
| B．Watch some TV shows before bedtime. |
| C．Reduce the screen time before sleep. |
| D．Take regular exercise every day. |
【推荐3】Simple Tricks to Get Rid of Dark Circles Under Eyes
Forget getting a corrective operation or a face lift just to get rid of those annoying dark circles under your eyes. We have gathered four simple tricks you can do at any time.
Change your diet
Yes, unfortunately your diet could be one of the causes of those eye circles and swelling(肿胀). And when you're flying, it can be really difficult to keep a healthy and balanced diet.
Cool tea bags
Here's the thing about friction—it causes skin pigmentation to darken. If you happen to be one of those people who constantly rub their eyes, here is an important reason why you should stop immediately. We know it can be hard when flying, but something as simple as not rubbing your eyes makes all the difference.
Get a retinoid cream(维甲酸乳膏)
Retinoids are a perfect solution for the area surrounding your eyes.
| A．Stop rubbing your eyes |
| B．Tea fans, this one is for you |
| C．So just keep them in your mind |
| D．But remember what you should do |
| E．Salty foods and alcohol cause swelling |
| F．Eat as much eye-friendly food as possible |
| G．The reason is that they quickly reduce discoloration |
【推荐1】Some Italian architects have completed the first 3D-printed home made from clay recently. It is called TECLA, which comes from “technology” and “clay”.
Its founder, Mario Cucinella, points out that building homes from earth is not new. Adobe-made from a mix of earth, water and organic material-is one of the world’s earliest construction materials, known for its firmness, and bio-degradability. He hopes that its design can become a practical option to house people who lack adequate housing due to financial issues.
Over the past few years, many 3D-printed homes and communities have been conceptualized, promising low construction costs. But while previous structures were built using concrete or plastic, TECLA was mainly built from soil at the site mixed with water and fibers from rice husks. Cucinella believes this approach can be adopted in different parts of the world, using whatever local materials are available, and could be particularly helpful in remote areas, where industrial construction materials are harder to come by.
Printing with clay has its drawbacks. It’s a much slower process than quick-drying concrete 3D-printed homes and all-clay skyscrapers are not likely in the future. However, the use of available soil and the program’s ease of construction mean that TECLA could be well-suited to provide housing in many different countries. It is estimated that by 2030, 3 billion people will require access to accessible and affordable residences. “You can build this kind of house in many more places when you are not dependent on some specific product,” Cucinella explained.
TECLA has drawn wide attention. “I’m not in the position to say this will be the future of all houses on the planet, “Russo, another 3D-printing architect said. However, he added, “I think this revolution of 3D printing is to give people a degree of freedom in how to do things, without being connected to a big, professional industry.”
1. What’s the purpose of TECLA?| A．To make 3D-printed homes firmer. |
| B．To assist in solving housing issues. |
| C．To provide alternatives for house buyers. |
| D．To help the poor through financial difficulty. |
| A．It’s quite expensive. |
| B．It takes a shorter time. |
| C．It’s a demanding process. |
| D．It’s flexible in material selection. |
| A．Favorable. | B．Critical. | C．Doubtful. | D．Tolerant. |
| A．A design that can replace the previous patterns. |
| B．A technology that takes the lead in architecture. |
| C．A structure where tradition meets new technology. |
| D．A trend where technology is coupled with architecture. |
【推荐2】A table-waiting robot cat built by a Chinese technology firm can carry plates of food, navigate a restaurant, miaow（喵喵叫）at diners—and even react to having its ears stroked.
Making its debut at the 2020 Consumer Electronics Show in Las Vegas, the so-called BellaBot was built for Chinese restaurants lacking enough waiters. It is the brainchild （智慧结晶）of the Chinese robotics and artificial intelligence firm PuduTech.
It features four shelves in the center of its tower-like body to carry plates. Having been loaded up with meals by its human colleagues, the cat-themed robotic waiter miaows when it delivers food to diners to encourage them to take their plates. If customers thank BellaBot by stroking its ears, it will initially respond with a look of pleasure on its on-board screen, which displays animations of a cat's face. “The owner's hand is so warm,” BellaBot has been programmed to respond.
However—much like a real cat—the robot’s reaction soon changes if it is petted for too long. “It gets mad to remind you not to interrupt its job,” the designers introduced.
The BellaBot waiter robot is a more personality-rich update to PuduTech's previous model, which featured a more utilitarian （实用主义的）design and user interface. Both BellaBot and its predecessor were designed with a particular mind to Chinese restaurateurs which are often short of waiting staff.
In a real-world food-service setting, however, BellaBot may find it difficult to operate at peak times. Nevertheless, restaurants are expected to increase their trust on automation—whether in the form of robotic waiting staff or otherwise.
Furthermore, the technology improvements of robotic waiters designs will be grown steadily, especially better at communicating with humans and tackling new activities.
1. Why did the technology firm create the BellaBot?| A．Because the restaurant can react to it. |
| B．Because it is the brainchild of the Chinese robotics and Al firm. |
| C．Because the Chinese scientists want to show their talent to the world. |
| D．Because it is can be used when Chinese restaurants are short of enough waiters. |
| A．The customers touch the robotic waiters’ ears. |
| B．The customers are encouraged to take their plates. |
| C．The human colleagues have loaded up the meals on robotic waiters. |
| D．The robotic waiters display animations of a cat's face on their on- board screen. |
| A．It wants to remind you to get mad. |
| B．It wants to remind you to pet it again. |
| C．It wants to remind you not to help its work. |
| D．It wants to remind you not to stop its work. |
| A．Doubtful. | B．Positive. |
| C．Negative. | D．Ambiguous. |
【推荐3】The original Blade Runner film took place in an imagined Los Angeles 2019, a futuristic city where acid rain fell from skies crowded with "skimmers": flying cars that zipped along aerial highways. Since the film's 1982 debut, technology has advanced in ways that Hollywood might never have predicted.
In fact, flying cars are real — and they could shape how we commute, work and live over the coming decades. Advances in battery energy density, materials science and computer simulation have spurred the development of a range of personal flying vehicles.
While these aircraft may not look exactly like Blade Runner's imaginings, they are also not all that far off either. Far smaller than a commercial plane, most are designed with rotors (螺旋桨) instead of wings, which allow for vertical takeoffs and landings. Most importantly, these vehicles are designed to offer faster commutes than traditional modes of transit for individuals, especially in cities with heavy traffic.
At the moment, the autonomous urban aircraft market is still a bit of a Wild West. Dozens of start-up companies are competing to develop commercial jetpacks, flying motorbikes and personal air taxis. Meanwhile, aviation (航空) authorities are currently hashing out the policies and safety standards that will govern this new realm of transport.
Germany-based Volocopter, for instance, has marketed its VoloCity craft as the first commercially licensed electrically powered air taxi, a vehicle which will eventually be able to run without a pilot.“It's like an Uber Black or any other premium service,” says Fabien Nestmann, vice president of public affairs at Volocopter.
With a few key differences, that is. Initially, the VoloCity will only have room for a single passenger. That will mean a higher cost per ride at first. But eventually, says Nestmann, the company's goal is to make the cost competitive with, say, an Uber Black. “We don't want this to be a toy for the wealthy, but rather part of a well-integrated journey for anyone in an urban area," he says." Everyone should have the option to walk, be driven, cycle or fly."
Increasing numbers of flying cars will naturally give rise to a changing layout in the way our cities are structured as cities grow taller, rooftop landings expand and air highways connect super sky-scrapers, freeing up space below. Fewer cars on the ground will reduce congestion (交通拥堵) and may give rise to parks and green spaces. “In the long run — 2045 and onward — businesses and green spaces will become much more integrated.” says Kopardekar. “While we may not ever eliminate metros and roads, we might be able to reduce their footprint with these machines.”
1. What does paragraph 3 mainly talk about?| A．The advantage and disadvantage of flying cars. |
| B．The features of today's real flying cars. |
| C．The prospect of flying cars in crowded cities. |
| D．The differences between flying cars in real life and the film. |
| A．a terrible mess | B．a big challenge |
| C．something in rapid growth | D．something in the early stages |
| A．They will increase traffic congestion and reducc grcen spaces. |
| B．They will lead to more integrated businesses and green spaces. |
| C．They will require the expansion of roads and metros in cities. |
| D．They will eliminate the need for traditional modes of transit. |
| A．Its design was inspired by the flying cars in the film Blade Runner. |
| B．It is designed with wings, allowing for easy takeoffs and landings. |
| C．It will become ultimately driverless, making it fully autonomous. |
| D．It can accommodate multiple passengers with competitive pricing. |
| A．Blade Rmer's flying cars will eventually replace all other vehicles |
| B．It will be hard for aviation authorities to regulate autonomous aircraft |
| C．Volocopter is the first company to develop electric air taxis |
| D．The widespread use of flying cars will lead to changes in city design |
【推荐1】The UK's first fully solar-powered home, which removes the need to ever receive a gas or electricity bill again, has gone on sale, but it will cost you £1.2 million.
The timber-framed home in Great Glen, Leicestershire, contains a number of “zero-carbon feature” including solar electric energy, triple glazing and rainwater storage. It is entirely heated by underground water-filled tubes that are warmed by solar energy from rooftop panels. The house was designed and built by Caplin Homes and covers two acres of land. The design and construction, down to the materials, were used specifically for their low carbon footprint.
The solar panels on the roof of the five-bedroom house are called hybrids because they collect both electrical and thermal energy. Solar walls preheat incoming air, and an Earth Energy Bank (EEB) and heat pump can store heat, and get it back for use when temperatures drop. The south-facing triple-glazed windows are said to also improve the house's energy management during the winter.
All the technologies are controlled by a control system, which monitors the inside and outside temperatures, how much energy is being received by the solar panels, and the heat levels in the EE domestic hot water tank. Due to its low energy design, the Solar House is expected to only require heat from the EEB for about 10 weeks of the year.
For £1.2 million, buyers also get two garages. Estate agent (房地产经纪人) Anthony Fox said the possibility of no utility bills was a big draw for potential owners: the idea is that your bills pretty much disappear and the house is self-sustaining and self-sufficient. That was a big aspect for most of the people who came to have a look around. “We had a lot of interest on the open day. There were some strong considerations to buy there and then. Everyone was very keen to learn how the house worked.” He added.
1. Which is true about the UK’s first fully solar-powered home?| A．It is directly heated by rooftop panels. |
| B．It has a set of heat-storage device available. |
| C．All of its materials are not environmentally friendly. |
| D．Its walls can keep cold air from coming in to store heat. |
| A．The monitor of the temperature. |
| B．The amount of the received energy. |
| C．The function of the control system. |
| D．The significance of the new technologies. |
| A．No gas or electricity bill. | B．Two additional garages. |
| C．Unique structure of the house. | D．Only £1.2 million for the house. |
| A．To advertise a zero-carbon house. |
| B．To recommend an amazing house. |
| C．To introduce a solar-powered house. |
| D．To explain how the low-energy house works. |
【推荐2】Fanning is a musician and hotel owner born in Ireland, and now he lives deep in the Appalachian Mountains of the United States. “The Irish have a song and play music nearly every day.” Said Fanning. “Every weekend, my family will play music in the house.” Like Fanning, many people in the area continue the traditions from their family’s immigrant history, including a kind of music called old-time.
Old-time music comes from the Appalachian Mountains, a system of mountains along the eastern part of the United States. In the 18th century, many Europeans from Ireland, Scotland, and Germany arrived in the area to begin new lives. Reflecting the cultures that settled there, the roots of old-time music are in the traditional music of these European countries. Although the US became their home, these Appalachian communities continued the European music and dance traditions they loved. Over time, the music mixed with that of African slaves and became what is now called old-time music.
The earliest purpose of the music was for dancing. Life in the mountains was hard work. Music and dancing provided the Appalachians with a much needed break from the labor of the day. And it brought people of different generations together. In small Appalachian towns in the past, there was always a musician in the neighborhood. Young people would study the art under him or her.
Old-time music is learned by ear. It’s a much more arduous kind of music than other music. There’re no written notes, so people have to learn it all by ear and try to reproduce the sound. Therefore, it needs more time and effort to master it. Old-time musicians might not read music, but they can easily put a song together.
Old-time songs mainly describe what happened in the past. Some called “spiritual” are based in the the Christain religion. Others are American civil war songs. And, many are about the life and land that surround the songwriter. But some of the earliest songs go back to the music’s European roots.
These days, oid-time music is not often heard over the radio. But it still lives on strongly in the communities where it came from.
1. What can we learn from Fanning’s words?| A．Music is a part of his daily life. |
| B．their music is popular in America. |
| C．Music reminds them of their history. |
| D．Music unites people of different races. |
| A．American music and European music. |
| B．Ancient European and Indian music. |
| C．European music and African music. |
| D．Music created in the 18th century. |
| A．Killing free time and educating the young. |
| B．Entertaining people and linking generations. |
| C．Encouraging hard work and recording history. |
| D．Building healthy lifestyles and uniting nations. |
| A．Traditional. | B．Difficult. | C．Popular. | D．Varied. |
| A．Natural beauty. | B．Love stories. |
| C．People’s wishes. | D．The history. |
【推荐3】Plans to bring wild tigers back to their original home , their historical range(历史分布范围） in the IliBalkhash region, have been announced by Kazakhstan( 哈萨克斯坦 ) and an agreement with World Wide Fund for Nature (WWF) to conduct a tiger reintroduction program has been signed . “It will not only bring wild tigers back to their original home, but also protect the unique ecosystem of the IliBalkhash region，” said Askar Myrzakhmetov, the Minister of Agriculture of the Republic of Kazakhstan.
If successful, Kazakhstan will be the first country in the world to bring wild tigers back to an entire region where they have died out for nearly half a century. Tiger reintroduction projects have only been achieved within national borders and in areas that are considered current tiger habitats . Kazakhstan's tiger reintroduction program is unique and it badly requires the restoration of a vast forest that is part of the wild tiger's historical range.
Since the beginning of the 20th century, wild tigers have lost over 90 per cent of their historical range. Wild tigers have completely disappeared from the region since the late 1940s, due to the loss of habitat. To prepare for the return of wild tigers, on 1st January 2018 Kazakhstan will set up a new nature reserve in the southwestern IliBalkhash, in order to restore the unique forest habitat. This will include the protection of existing wildlife, and reintroducing important prey ( 猎物 ), such as the endangered wild Bactrian deer（中亚红鹿).
Restoring tigers will also help protect Lake Balkhash and prevent it from repeating the fate of the Aral Sea, formerly the world's fourth largest lake and now 10 percent of its original size. “The hard work remains ahead of us. We have to spare no effort to make this region ready for tigers and involve all the relevant people to make this happen. That means dealing with illegal activities, having these people who govern parks be welltrained and equipped, increasing prey populations and involving local communities，” said Ekaterina Vorobyeva, Director of the WWF program.
1. What is Askar Myrzakhmetov's attitude toward the tiger reintroduction program?| A．Doubtful. | B．Favorable. |
| C．Concerned. | D．Disapproving. |
| A．The increasing loss of prey. | B．The evolution of the species. |
| C．The lack of natural living places. | D．The serious environmental pollution. |
| A．Regulating human activities. | B．Limiting the number of prey. |
| C．Building a reserve for tigers only. | D．Training tigers to be more adaptable. |
| A．Efforts to restore forests in Kazakhstan |
| B．Bringing tigers back home to Kazakhstan |
| C．Attempts to handle illegal activities effectively |
| D．Preventing tigers disappearing in Kazakhstan |
