Self-driving cars are hitting city streets like never before. In August the California Public Utilities Commission (CPUC) granted (授予) two companies, Cruise and Waymo, permits to run driverless robo-taxis 24/7 in San Francisco and to charge passengers for those rides. This was just the latest in a series of green lights that have allowed progressively more freedom for autonomous vehicles (AVs) in the city in recent years.
Almost immediately, Cruise was criticized for its vehicles behaving unpredictably. One blocked the road outside a large music festival, and another got stuck in wet concrete. The incidents have brought renewed attention to the potential difficulties of integrating self-driving cars into the urban environment.
Yet despite some ongoing opposition, self-driving car companies have continued to expand testing and operations to more US cities. Many supporters say these vehicles could offer a safer alternative to human drivers, make transportation accessible to more people, improve traffic flows around cities and decrease the environmental impact of cars. So far, though, most of those promised benefits remain squarely in a possible future. Meanwhile, here in the present, complications have become plainly apparent.
AVs, such as those operated by Cruise and Waymo, shouldn’t be confused with commercially available cars, such as electric cars, which come with some driver-assistance features. Unlike those vehicles, which require a human driver to oversee control at all times, robo-taxis run on the road without a person monitoring and managing each movement from behind a steering wheel (方向盘). This is made possible by a very detailed internal map.
Waymo and Cruise maintain that their AVs are safer than human drivers. Both companies have released data that they claim support this, yet some researchers have their doubts. “I actually think there is not yet enough data available to the public, including researchers like me, to be able to judge relative safety,” says Steven Shladover, an engineer at the University of California.
1. What is the CPUC’s main purpose of issuing the permits?| A．To promote autonomous vehicles. | B．To advocate sustainable practices. |
| C．To upgrade public transportation. | D．To reduce traffic at peak periods. |
| A．They have charged passengers too much. |
| B．They occupy private parking spaces. |
| C．They badly affect the urban environment. |
| D．They consume large amounts of fuel. |
| A．They require more qualified human drivers. |
| B．They are more dependent on the internal map. |
| C．They will meet customers at a lower price. |
| D．They are smarter to handle a difficult situation. |
| A．We should give freedom to car producers. |
| B．Driverless cars will improve city planning. |
| C．All researchers support driverless robo-taxis. |
| D．It’s too early to declare AVs are safe enough. |
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【推荐1】Strategically adding weak points along microscopic chains called polymers (高分子聚合物) actually makes them harder to tear, researchers report in the June 23 Science. Polymers are used in car tires, and therefore the findings could help reduce plastic pollution as tires wear down over time.
When tires rub against the road, they drop microplastics of rubber and plastic polymers, which pollute waterways and air. Every year, tires release an estimated 6 million metric tons of these microplastics into environment. Stronger polymers that break apart less easily could limit the amount of particles shed annually.
To make such tough materials, Stephen Craig, a chemist at Duke University, and colleagues added molecules called cross-linkers to the polymers. These cross-linkers connected these polymer chains to their many neighbors, and they were specifically designed to break apart easily. At the microscopic scale, the polymers act like a tangle (乱团) of spaghetti with the cross-linkers holding them all together and helping them keep their shape, says Craig’s collaborator Shu Wang, a chemist at MIT. When the team stretched the polymer spaghetti, the individual cross-linkers broke easily, as expected. But the larger tangle material required more force to break than they expected.
The secret to the increased toughness lies in the path the tear has to take, Craig says. The tear goes through the easy-to-break cross-linkers rather than through the tougher polymer chains. Each broken connection follows the path of least resistance but avoiding the long polymer chains means breaking many cross-linkers, which requires more stretching force overall.
This isn’t the first time researchers have used weak connectors to make polymers stronger. But unlike in similar materials, the increased toughness doesn’t come at the expense of other beneficial properties like stiffness (风度). Craig says he hopes the findings will help extend the lifetimes of car tires and plastics, potentially limiting annual microplastic pollution.
1. What benefit does the new material bring?| A．It meets the road standard. | B．It weakens plastic polymers. |
| C．It releases less microplastics. | D．It reduces the cost of car tires. |
| A．It follows the pattern of spaghetti. | B．It is designed to fall apart easily. |
| C．The polymers help keep its shape. | D．The larger tangle is harder to break. |
| A．The weakness of the cross-linker. | B．The strength of the polymer chains. |
| C．The number of the cross-linkers used. | D．The path the tear takes through the material. |
| A．It initially uses weak connectors. | B．It sacrifices stiffness for toughness. |
| C．It lengthens the lifespan of car tires. | D．It removes annual microplastic pollution. |
【推荐2】The 17 Sustainable (可持续) Development Gosls of the United Nations give us opportunities of our time-opportunities to terminate extreme poverty, to make sure that everyone can get food and clean water. In fact, there are many space services that can help us pursue the Sustainable Development Goals.
Communication satellites make it possible to make a phone call and have Internet service on Earth. This is particularly important during times of disaster recovery, When Typhoon Haiyan struck the Philippines, the local communication networks needed to be repaired, and teams brought in communication tools that could connect with satellites. This was useful during the time of repair and recovery.
In space, we have a laboratory on the International Space Station. The vehicle and everything inside are in a form of free fall around the earth, and they don’t experience the effect of gravity. And because of this, we call it “microgravity (微重力)”. When astronauts are in the microgravity environment, their bodies react as if they’re aging rapidly. Their bones and muscles weaken, and the systems of their bodies change. As scientists study how to keep astronauts healthy in space, we can take the exercises and techniques we use for astronauts and transfer (转用) them to improve our health here.
Often, as we develop technology for astronauts and exploration for spacecrafts, we can also transfer those inventions to help people on the earth. Filtration (过滤) system is one of the examples. It is a tool that liquid is passed through in order to remove any materials that are not wanted. With the help of filtration system, drinking clean water became possible for astronauts in space. The system is now being used around the world.
Space is also a great source of inspiration, through education, research and astronomy (天文学). Now, countries around the world are working at advancing their own development by increasing their local knowledge of engineering, science and space.
1. What does the underlined word “terminate” in Paragraph 1 probably mean?| A．Create. | B．End. | C．Help. | D．Monitor. |
| A．It is a state of free fall. | B．It widely exists on the earth. |
| C．It can be changed by people. | D．It brings harm to astronauts. |
| A．To encourage the exploration of space. | B．To promote the use of filtration system. |
| C．To show the transfer of space inventions. | D．To inspire people to invent more tools. |
| A．The Mystery of Outer Space Technologies. |
| B．Space Technologies We Can Use to Improve Life. |
| C．The Development of Advanced Space Technologies. |
| D．Sustainable Development of Science and Technology. |
【推荐3】Singapore's schools have become global role models with high results in international tests. But now they want to move, beyond this—towards something that encourages creativity and what they term "holistic(全面的) education".
Minister of Education, Heng Swee Keat, says this is "less about content knowledge", but "more about how to process information". He describes this challenge of innovating(创新) as being about to "tell truth from untruth, connect seemingly different things, and create knowledge even as the situation changes".
This approach aims to prepare today's students for the demands of the next 20 years. It means that schools are under more pressure, and will be given more freedom, to come up with creative ways to teach students. So instead of the traditional impressions of high-pressure Asian schools, with rows of heads buried in books, they are trying different approaches to learning.
To put this into practice, on a sunny April morning, 80 students from one of Singapore's top schools were traveling outdoors. The nine to ten-year-old from Rosyth School were on a "learning journey" in a park, with science topics and values such as caring for the environment.
"We are conducting a biopsy（活组织检查）to find out why a bee, a fish, a bird or a plant died strangely," said one student. "Is it because of human actions?"
They photographed "evidence" on smart phones and digital cameras, getting facts on plants and animal species. "They can really learn through hands-on experience and putting things into action," said moral education teacher, Joslyn Huang.
1. What are Singapore's schools famous for according to the passage?| A．Test results. | B．Strict management. |
| C．Teaching methods. | D．Learning environment. |
| A．Students' moral behavior. | B．Students' creative ability. |
| C．Students' content knowledge. | D．Students' hands-on experience. |
| A．To improve the environment. |
| B．To protect animals and plants. |
| C．To study the relationship between human actions and some animals' death. |
| D．To find out the relationship between human behaviors and climate changes. |
| A．By giving examples. | B．By making comparisons. |
| C．By listing figures. | D．By analyzing cause and effect. |
【推荐1】When we think of food farming we usually think of green fields in the country, outside the city. Sam Chee works on a very different type of farm, in the center of the Canadian city of Toronto. “We grow fruit, vegetables and herbs,” says Sam. “But not many people know the farm is here. You can’t see it from the street. We’re on top of an office building, 50 meters above the ground.”
Rooftop farming is becoming popular in cities like Toronto, New York and London. The roofs of buildings are often just wasted space, but this space can be used for growing good fresh food, right in the middle of the city. Sam explains how it works. “We grow everything in big boxes —there are hundreds of them. We catch rainwater to water the plants when the weather is dry.”
The rooftop farm where Sam works belongs to a restaurant called Green Garden, on the ground floor of the building. The farm produces about half the restaurant’s fruit and vegetables. Sam believes that the rooftop farm is what makes Green Garden special. “We help to keep food production local. We don’t need to transport this food from anywhere and that saves energy. It’s better for the environment.”
The food from the rooftop is fresher too. “When the fruit and vegetables are ripe we can pick them and use them right away. They taste better when they’re really fresh,” says Sam. “I hope that there will be more rooftop farms in the city soon. It could be the farming of the future.”
1. Green Garden’s rooftop farm is ________.| A．the only one in the world | B．in the middle of a small town |
| C．one of many in cities around the world | D．near the countryside of a city |
| A．it is much cheaper and fresher | B．it tastes better and is better for the environment |
| C．it uses space which was being wasted | D．it can’t be bought in the local stores |
| A．The farm is on the top of a teaching building 50 meters above the ground. |
| B．The plants are watered by collected rainwater when necessary. |
| C．You can find more rooftop farms in the country than in the city. |
| D．When they pick the fruit and vegetables, they won’t use them at once. |
| A．To describe what rooftop farming is by giving an example. |
| B．To describe why rooftop farming has become very popular in Canada. |
| C．To tell the story of the man who first started rooftop farming. |
| D．To encourage people to build as many rooftop farms as possible |
【推荐2】Most city parks are places where you can escape from big, ugly structures of metal and stone. The Manhattan High Line is different. Raised 25 feet above the ground, this large metal structure once supported a rail line. The line opened in 1934 to bring trains directly into factories. It was hardly used after the 1960s, and much of it was torn down. However, one part remained in a region of Manhattan called Chelsea. Chelsea was becoming high-class as restaurants, art galleries and apartments were built, but the ugly railway structure remained as a dead weight. Everyone knew that at some time, it would have to be removed.
But the High Line was not destroyed. In fact, now the old rail line serves as one of the most peaceful places in the city. It holds an incredible park, with beautiful gardens and great views of the city. The idea to turn the rail line into a park came from Joshua David and Robert Hammond. In 1999, they attended a meeting to decide how to deal with the High Line. David and Hammond were the only people at the meeting interested in saving the historical structure. Later on, when they asked railway officials to take them up to look at the High Line, they saw a mile and a hall of wild flowers growing in the middle of the city, and they realized that the High Line had potential to become a park. There was growing interest in improving city centers, and so the project quickly developed and money for construction was easily collected.
The first part of the High Line opened in 2009 and immediately became popular with tourists and locals alike. Each part of the park has a different atmosphere. Some areas are like balconies (阳台) with wonderful city views. Where the rail line goes between buildings, trees are thickly planted. Other sections have wide lawns (草坪) and walkways with wild flowers. Only the final section remains the way it has been for the last fifty years.
1. What does the underlined part “a dead weight” in paragraph 1 mean?| A．Something with historical interest. | B．Something with potential to be better. |
| C．Something which is a danger to people. | D．Something useless which slows progress. |
| A．They wanted to reopen the train line. |
| B．They thought it had historical value. |
| C．They were interested in improving the city. |
| D．They thought it would become a good park. |
| A．Only part of the line remains. |
| B．The railway companies still use the line. |
| C．It began to become popular in the 1960. |
| D．It was designed by David and Hammond. |
| A．Closing a train line. | B．An unlikely place for a park. |
| C．Protection of cultural relics. | D．Improving city transport. |
【推荐3】More than a quarter of parents use a device to track or monitor their kids’ online activity, finds a survey from Common Sense Media and Survey Monkey. It’s far more than the percentage of teens (15%) who think their parents are tracking or monitoring what they do online. Whether all that snooping (调查) is effective seems unclear. Only 30% of teens who responded to the survey said their parents were “extremely” aware or “very” aware of what they do online. By comparison, 52% of parents believed they were “very” aware of their kids’ web activity.
“There’s a pretty big difference between parents who say they know and what kids say parents know,” said Michael Robb, director of research for Common Sense Media. The online survey was among a national sample of 884 teens and 3,282 parents of teens.
Options for tracking kids’ online activities vary from tools for your router capable of tracking the websites users visit to apps letting you review your child’s smart phone call logs and text messages.
Devorah Heitner, author of the book Screen Wise: Helping Kids Thrive (and Survive) In Their Digital World, suggests mentoring kids about best online practices instead of monitoring. If parents do choose to monitor, they should talk with their kids first. “You have to really ask yourself what you think you’re going to learn by monitoring your kid,” she said, “What’s your plan of action if you see something that concerns you?”
Other findings from the survey: Snapchat is the app that causes the most anxiety for parents. The survey found 29% said the messaging apps make them most nervous, followed by Facebook at 16%.Teens don't like Facebook as much as Snapchat or Instagram. More than three-quarters of teens said they use both messaging apps, but only 49% said they use Facebook, while 42% said they use Twitter.
Robb said Common Sense Media plans to partner with Survey Monkey on future online polls because the pace of technology is so rapid. “These surveys will be a quicker way to take the pulse of parents and teens.”
1. Which of the following is true according to the survey?| A．Snapchat is the biggest worry for both parents and kids |
| B．Some parents choose to use apps to track their kids’ online activity. |
| C．Twitter will cooperate with Facebook on future online polls. |
| D．Kids are aware that over 25% of parents use a device to track their online activity. |
| A．inform that the snooping seems to be ineffective |
| B．warn that the kids are being monitored by their parents |
| C．predict that more and more parents will monitor their kids’ online activities |
| D．indicate that the number of parents tracking teens online is beyond the kids’ imagination |
| A．Parents had better not monitor their kids’ online activities. |
| B．Parents should communicate with their kids while monitoring their online activities. |
| C．Parents need to ask their kids permission before guiding them about online activities. |
| D．Parents must often reflect on their purpose of monitoring their kids’ online activities. |
| A．It is too young for kids to go online. |
| B．Teens don’t like Facebook at all. |
| C．Michael Robb is confident of the future online polls. |
| D．Common Sense Media plans to partner with Survey Monkey in the future. |
