1 . Can a small group of drones (无人机) guarantee the safety and reliability of railways and, at the same time, help railway operators save billions of euros each year? That is the very likely future of applying today’s “eyes in the sky” technology to make sure that the millions of kilometres of rail tracks and infrastructure (基础设施) worldwide are safe for trains on a 24/7 basis.

Drones are already being used to examine high-tension electrical lines. They could do precisely the same thing to inspect railway lines and other vital aspects of rail infrastructure such as the correct position of railway tracks and switching points. The more regularly they can be inspected, the more railway safety, reliability and on-time performance will be improved. Costs would be cut and operations would be more efficient (高效) across the board.

That includes huge savings in maintenance costs and better protection of railway personnel safety. It is calculated that European railways alone spend approximately 20 billion euros a year on maintenance, including sending maintenance staff, often at night, to inspect and repair the rail infrastructure. That can be dangerous work that could be avoided with drones assisting the crews’ efforts.

By using the latest technologies, drones could also start providing higher-value services for railways, detecting faults in the rail or switches, before they can cause any safety problems. To perform these tasks, drones for rail don’t need to be flying overhead. Engineers are now working on a new concept: the rail drones of the future. They will be moving on the track ahead of the train, and programmed to run autonomously. Very small drones with advanced sensors and AI and travelling ahead of the train could guide it like a co-pilot. With their ability to see ahead, they could signal any problem, so that fast-moving trains would be able to react in time.

3 . Languages have been coming and going for thousands of years, but in recent times there has been less coming and a lot more going. When the world was still populated by hunter-gatherers, small, tightly knit(联系) groups developed their own patterns of speech independent of each other. Some language experts believe that 10,000 years ago, when the world had just five to ten million people, they spoke perhaps 12,000 languages between them.

Soon afterwards, many of those people started settling down to become farmers, and their languages too became more settled and fewer in number. In recent centuries, trade, industrialization, the development of the nation-state and the spread of universal compulsory education, especially globalisation and better communications in the past few decades, all have caused many languages to disappear, and dominant languages such as English, Spanish and Chinese are increasingly taking over.

At present, the world has about 6,800 languages. The distribution of these languages is hugely uneven. The general rule is that mild zones have relatively few languages. Often spoken by many people while hot, wet zones have lots, often spoken by small numbers. Europe has only around 200 Languages: the Americas about 1,000, Africa 2,400; and Asia and the Pacific perhaps 3,200, of which Papua New Guinea alone accounts for well over 800. The median number(中位数) of speakers is a mere 6，000, which means that half the worlds languages are spoken by fewer people than that.

Already well over 400 of the total of 6,800 languages are close to extinction(消亡), with only a few elderly speakers left. Pick, at random, Busuu in Cameroon (eight remaining speakers), Chiapaneco in Mexico(150). Lipan Apache in the United States(two or three) or Wadjigu in Australia (one, with a question-mark): none of these seems to have much chance of survival.

4 . People refer to never forgetting how to ride a bike or throw a baseball as examples of “muscle memory”, the result of a motor learning.     1     It is a phenomenon that previously trained muscles acquire strength after a period of disuse.

Previous research has shown that the changes actually persist in the muscles themselves. In one study of mice, the results suggest that after nuclei in muscle cells multiply in response to an overload of training, those extra nuclei aren’t lost during subsequent periods of inactivity. They are retained (保留), essentially waiting to be reactivated. If you fell off the fitness wagon (马车) during the pandemic, don’t be frustrated. Once you have got additional nuclei, you are banking the capacity.     2     In fact, a recent study revealed that less than eight weeks of retraining were needed to regain your former fitness. It depends on how fit you were initially, how long the layoff was, how old you are and how long you’d been exercising.

    3     It means you still have a distinct advantage when it comes to regaining your former level of fitness. And the principle applies to both resistance training and endurance training. The best way to regain your muscle memory is to start at a level below what you were accustomed to doing, and then gradually increase in terms of duration, frequency, then intensity.     4    

Ultimately, muscle memory is a payoff for all the past work you put into learning a sport.     5     You will never know how much muscle memory you may have until you start training again.

5 . Monkeys seem to have a way with numbers.

A team of researchers trained three Rhesus monkeys to associate 26 clearly different symbols consisting of numbers and selective letters with 0-25 drops of water or juice as a reward. The researchers then tested how the monkeys combined—or added—the symbols to get the reward.

Here’s how Harvard Medical School scientist Margaret Livingstone, who led the team, described the experiment: In their cages the monkeys were provided with touch screens. On one part of the screen, a symbol would appear, and on the other side two symbols inside a circle were shown. For example, the number 7 would flash on one side of the screen and the other end would have 9 and 8. If the monkeys touched the left side of the screen they would be rewarded with seven drops of water or juice; if they went for the circle, they would be rewarded with the sum of the numbers—17 in this example.

After running hundreds of tests, the researchers noted that the monkeys would go for the higher values more than half the time, indicating that they were performing a calculation, not just memorizing the value of each combination.

When the team examined the results of the experiment more closely, they noticed that the monkeys tended to underestimate(低估) a sum compared with a single symbol when the two were close in value—sometimes choosing, for example, a 13 over the sum of 8 and 6. The underestimation was systematic: When adding two numbers, the monkeys always paid attention to the larger of the two, and then added only a fraction(小部分) of the smaller number to it.

“This indicates that there is a certain way quantity is represented in their brains, ”Dr. Livingstone says. “But in this experiment what they’re doing is paying more attention to the big number than the little one.”

6 . Teens and younger children are reading a lot less for fun, according to a Common Sense Media report published Monday.

While the decline over the past decade is steep for teen readers, some data in the report shows that reading remains a big part of many children’s lives, and indicates how parents might help encourage more reading.

According to the report’s key findings, “the proportion (比例) who say they ‘hardly ever’ read for fun has gone from 8 percent of 13-year-olds and 9 percent of 17-year-olds in 1984 to 22 percent and 27 percent respectively today.”

The report data shows that pleasure reading levels for younger children, ages 2—8, remain largely the same. But the amount of time spent in reading each session has declined, from closer to an hour or more to closer to a half hour per session.

When it comes to technology and reading, the report does little to counsel(建议) parents looking for data about the effect of e-readers and tablets on reading. It does point out that many parents still limit electronic reading, mainly due to concerns about increased screen time.

The most hopeful data shared in the report shows clear evidence of parents serving as examples and important guides for their kids when it comes to reading. Data shows that kids and teens who do read frequently, compared to infrequent readers, have more books in the home, more books purchased for them, parents who read more often, and parents who set aside time for them to read.

As the end of school approaches, and school vacation reading lists loom(逼近) ahead, parents might take this chance to step in and make their own summer reading list and plan a family trip to the library or bookstore.

7 . I work with Volunteers for Wildlife, a rescue and education organization at Bailey Arboretum in Locust Valley. Trying to help injured, displaced or sick creatures can be heartbreaking; survival is never certain. However, when it works, it is simply beautiful.

I got a rescue call from a woman in Muttontown. She had found a young owl(猫头鹰) on the ground. When I arrived, I saw a 2-to 3-week-old owl. It had already been placed in a carrier for safety.

I examined the chick(雏鸟) and it seemed fine. If I could locate the nest, I might have been able to put it back, but no luck. My next work was to construct a nest and anchor it in a tree.

The homeowner was very helpful. A wire basket was found. I put some pine branches into the basket to make this nest safe and comfortable. I placed the chick in the nest, and it quickly calmed down.

Now all that was needed were the parents, but they were absent. I gave the homeowner a recording of the hunger screams of owl chicks. These advertise the presence of chicks to adults; they might also encourage our chick to start calling as well. I gave the owner as much information as possible and headed home to see what news the night might bring.

A nervous night to be sure, but sometimes the spirits of nature smile on us all! The homeowner called to say that the parents had responded to the recordings. I drove over and saw the chick in the nest looking healthy and active. And it was accompanied in the nest by the greatest sight of all — LUNCH! The parents had done their duty and would probably continue to do so.

2. 可以适当增加细节，以使行文连贯。

9 . Adults understand what it feels like to be flooded with objects. Why do we often assume that more is more when it comes to kids and their belongings? The good news is that I can help my own kids learn earlier than I did how to live more with less.

I found the pre-holidays a good time to encourage young children to donate less-used things, and it worked. Because of our efforts, our daughter Georgia did decide to donate a large bag of toys to a little girl whose mother was unable to pay for her holiday due to illness. She chose to sell a few larger objects that were less often used when we promised to put the money into her school fund(基金)(our kindergarten daughter is serious about becoming a doctor)

For weeks, I've been thinking of bigger, deeper questions: How do we make it a habit for them? And how do we train ourselves to help them live with, need, and use less? Yesterday, I sat with my son, Shepherd, determined to test my own theory on this. I decided to play with him with only one toy for as long as it would keep his interest. I expected that one toy would keep his attention for about five minutes, ten minutes, max. I chose a red rubber ball-simple, universally available. We passed it, he tried to put it in his mouth, he tried bouncing it, rolling it, sitting on it, throwing it. It was totally, completely enough for him. Before I knew it an hour had passed and it was time to move on to lunch.

We both became absorbed in the simplicity of playing together. He had my full attention and I had his. My little experiment to find joy in a single object worked for both of us.