【推荐3】Maybe in the near future, driverless cars may become common on the roads. Driverless cars have already been test-driven thousands of miles.     1     For instance, it helps reduce the number of accidents and traffic jams.

    2     That is because there are many issues that must be solved before the widespread use of them. One problem is that a driverless car cannot predict problems far down the road like a driver can. The driverless cars react to an emergency only when it actually occurs. For instance, a driver starts to slow down when he sees a child riding her skateboard directly into the road 0.2 km away.     3    

Driverless cars are not suitable for extreme weather conditions.     4     They don't predict or "feel" that the roads have become icy like an experienced driver would. For instance, when a road is icy, a human driver would step on the brakes more gently than when the roads are clean and dry.

Another issue is that driverless cars have maps programmed into their memory, but these maps aren't always updated and accurate. New roads are built, and old roads are closed down.     5     Perhaps one day, driverless cars will be everywhere, but we are not ready for that just yet.

【推荐1】Language learning begins with listening. Children are greatly different in the amount of listening they do before they start speaking, and later starters are often long listeners. Most children will “obey” spoken instructions some time before they can speak, though the word “obey” is hardly accurate as a description of the eager and delighted cooperation usually shown by the children. Before they can speak, many children will also ask questions by gesture and by making questioning noises.

Any attempt to study the development from the noises babies make to their first spoken words leads to considerable difficulties. It is agreed that they enjoy making noises, and that during the first few months one or two noises sort themselves as particularly expressive as delight, pain, friendliness, and so on. But since these can’t be said to show the baby’s intention to communicate, they can hardly be regarded as early forms of language. It is agreed, too, that from about three months they play with sounds for enjoyment, and that by six months they are able to add new words to their store. This self-imitation leads on to deliberate imitation of sounds made or words spoken to them by other people. The problem then arises as to the point at which one can say that these imitations can be considered as speech.

It is a problem we need to get our teeth into. The meaning of a word depends on what a particular person means by it in a particular situation; and it is clear that what a child means by a word will change as he gains more experience of the world. Thus the use, at seven months, of “mama” as a greeting for his mother cannot be dismissed as a meaningless sound simply because he also uses it at another time for his father, his dog, or anything else he likes. Playful and meaningless imitation of what other people say continues after the child has begun to speak for himself. I doubt, however, whether anything is gained when parents take advantage of this ability in an attempt to teach new sounds.

【推荐2】The alarm sounds. Students swing their backpack over their shoulders, board the school bus, make their way to their homeroom and the bell rings - school is back. But for more homes in America, school looks more like students waking up, making their way to the dining room or home office, setting up laptops and learning in the comfort of home.

Virtual(虚拟的) schooling, defined as “a public school that offers only instruction in which students and teachers are separated by time and/or location, and interaction occurs via computers and/or telecommunications(电信) technologies'”, has increased over the past decade. According to the National Education Policy Center, enrollments(入学) in virtual schools increased by 17,000 students between 2015-16 and 2016-17 to 295,51 8 students.

For Arizona Virtual Academy, a full online public K-12 charter school, they use K12 Inc. curriculum. K12 serves students in all 50 states and more than 100 countries with digital learning platforms and technology, providing on line education. “We always are improving our platforms and the technology that we use to make sure that we're keeping up with the changing trends, not only with education but also with technology,'” Dr. Kelly Van Sande said. Another piece of new technology they've rolled out is a new app where parents can find virtual schools available in their area.

Carrie Faulkner chose to enroll two of her children in Arizona Virtual Academy. She says they've done schooling online in Chicago, in California, at restaurants, and on her cousin's floor in Kansas. “It doesn't matter whether he/her son) is on the couch, in his bed or at the kitchen table-he can do schooling wherever he wants to,” Faulkner said. “I wish they had it for me back when I was in school. That would have been awesome.”

【推荐3】The COVID-19 has led to a great demand for bikes and biking.Bike stores are struggling hard to keep up with the demand.In the United States,bike sales have seen their biggest jump since the 1970s.Sales of adult bikes in April of 2020 were three times as high as last year.The situation is similar in Asia and Europe.Around 90%of the bikes sold in the US are made in China.But because of the COVID-19,even the normal supply of bicycles wasn’t being created.That demand began to go up in mid-March,as people began looking for ways of getting around that didn’t involve crowded public transportation.Because biking happens in the open air,and the chance of catching the disease while riding is very low.

Biking has also grown more popular because it’s one of the few forms of exercise allowed in many lockdowns.With gyms and fitness centers shut down,biking fills a need for many active people.Families appreciate biking,too.With schools closed,and kids unable to hang out with their friends,biking is a welcome activity.Bikes are also practical.Many cities are seeing this as an opportunity to make their streets safer and greener.Cities around the world are adding miles and miles of bike lanes(车道)to their streets to encourage biking,New York says it will close off up to 160 kilometers of roads so they can be used by bikers and walkers.Paris has set up over 650 kilometers of new bike lanes.The United Kingdom plans to double its number of bike lanes.In Milan,Italy,35 kilometers of roads have been metamorphosed.

Though many of these bike lane additions are temporary,and some people assume these additions seem to destroy the overall beauty of cities,if changes in biking habits become permanent because of additions,they could seriously cut down car traffic and help make cities a lot greener.