【推荐1】Limiting kids’ recreational (消遣的) screen time to less than two hours a day, along with enough sleep and physical activity, is associated with improved cognition (认知) , according to a study published in The Lancet Child & Adolescent Health.

The study included about 4 ,500 US children aged 8 to11 and measured their habits against the Canadian 24 – Hour Movement Guidelines for Children and Youth. It found that 51% of the children got the recommended (建议的) 9 to 11 hours of uninterrupted sleep per night; 37% met the recreational screen time limit of two hours or less per day, while 18% met the physical activity recommendation of at least 60 minutes of accumulated physical activity a day. Only 5% of the children in the study met all three recommendations; 30% met none at all.

The researchers found that as each recommendation was met by a participant, there was a positive association with global cognition, which includes memory, attention, processing speed and language. Those who met all three had the most “superior” global cognition, followed by those meeting the sleep and screen time recommendation and finally the screen time recommendation alone, according to the study.

Other organizations, such as the American Academy of Pediatrics – have guidelines in place to help with the management of children’s screen time. The organization suggests putting realistic rules or limits in place for how long your children are on their screens, knowing who they are talking to and what they are doing. The amount recommended screen time depends on the age of the child. Besides, parents should also make sure to encourage physical activity and have bedroom rules such as creating “ tech-free zones”.

【推荐2】For people, many other animals, family matters. Consider how many jobs go to relatives. Or how an ant will cruelly attack intruder (入侵的) ants but rescue injured, closely related nest-mates. There are good evolutionary reasons to aid relatives, after all. Now, it seems, family feelings may stir in plants as well.

A Canadian biologist planted the seed of the idea more than a decade ago, but many plant biologists regarded it as heretical-plants lack the nervous systems that enable animals to recognize kin (家族), so how can they know their relatives? But with a series of recent findings, the belief that plants really do care for their most genetically close peers-in a quiet, planty way-is taking root. Some species control how far their roots spread, others change how many flowers they produce, and a few tilt (倾斜) or shift their leaves to minimize shading of neighboring plants, favoring related individuals.

“We need to recognize that plants not only sense whether it’s light or dark or if they’ve been touched, but also whom they are interacting with,” says Susan Dudley, a plant evolutionary ecologist, whose early plant kin recognition studies sparked the interest of many scientists.

Beyond broadening views of plant behavior, the new work may have a practical side. In September 2018, a team in China reported that rice planted with kin grows better, a finding that suggested family ties can be used to improve crop yields. “It seems anytime anyone looks for it, they find a kin effect,” says Andre Kessler, a chemical ecologist at Cornell University.

【推荐1】Certain forms of AI are indeed becoming ubiquitous. For example, algorithms (算法) carry out huge volumes of trading on our financial markets, self-driving cars are appearing on city streets, and our smartphones are translating from one language into another. These systems are sometimes faster and more perceptive than we humans are. But so far that is only true for the specific tasks for which the systems have been designed. That is something that some AI developers are now eager to change.

Some of today’s AI pioneers want to move on from today’s world of “weak” or “narrow” AI, to create “strong” or “full” AI, or what is often called artificial general intelligence (AGI). In some respects, today’s powerful computing machines already make our brains look weak. AGI could, its advocates say, work for us around the clock, and drawing on all available data, could suggest solutions to many problems. DM, a company focused on the development of AGI, has an ambition to “solve intelligence”. “If we’re successful,” their mission statement reads, “we believe this will be one of the most important and widely beneficial scientific advances ever made.”

Since the early days of AI, imagination has outpaced what is possible or even probable. In 1965, an imaginative mathematician called Irving Good predicted the eventual creation of an “ultra-intelligent machine…that can far surpass all the intellectual (智力的) activities of any man, however clever.” Good went on to suggest that “the first ultra-intelligent machine” could be “the last invention that man need ever make.”

Fears about the appearance of bad, powerful, man-made intelligent machines have been reinforced (强化) by many works of fiction — Mary Shelley’s Frankenstein and the Terminator film series, for example. But if AI does eventually prove to be our downfall, it is unlikely to be at the hands of human-shaped forms like these, with recognisably human motivations such as aggression (敌对行为). Instead, I agree with Oxford University philosopher Nick Bostrom, who believes that the heaviest risks from AGI do not come from a decision to turn against mankind but rather from a dogged pursuit of set objectives at the expense of everything else.

The promise and danger of true AGI are great. But all of today’s excited discussion about these possibilities presupposes the fact that we will be able to build these systems. And, having spoken to many of the world’s foremost AI researchers, I believe there is good reason to doubt that we will see AGI any time soon, if ever.

【推荐2】If you want to tell the history of the whole world, a history that does not privilege one part of humanity, you cannot do it through texts alone, because only some of the world has ever had texts, while most of the world, for most of the time, has not. Writing is one of humanity’s later achievements, and until fairly recently even many literate (有文字的) societies recorded their concerns not only in writing but in things.

Ideally a history would bring together texts and objects, and some chapters of this book are able to do just that, but in many cases we simply can’t. The clearest example of this between literate and non-literate history is perhaps the first conflict, at Botany Bay, between Captain Cook’s voyage and the Australian Aboriginals. From the English side, we have scientific reports and the captain’s record of that terrible day. From the Australian side, we have only a wooden shield (盾) dropped by a man in flight after his first experience of gunshot. If we want to reconstruct what was actually going on that day, the shield must be questioned and interpreted as deeply and strictly as the written reports.

In addition to the problem of miscomprehension from both sides, there are victories accidentally or deliberately twisted, especially when only the victors know how to write. Those who are on the losing side often have only their things to tell their stories. The Caribbean Taino, the Australian Aboriginals, the African people of Benin and the Incas, all of whom appear in this book, can speak to us now of their past achievements most powerfully through the objects they made: a history told through things gives them back a voice. When we consider contact (联系) between literate and non-literate societies such as these, all our first-hand accounts are necessarily twisted, only one half of a dialogue. If we are to find the other half of that conversation, we have to read not just the texts, but the objects.

What does the underlined word “conversation” in paragraph 3 refer to?

【推荐3】The other day, my sister and I were sitting in a restaurant, trying to have a conversation, but her children, four-year-old Willow and seven-year-old Luca, would not stop fighting. The arguments-over a fork, or who had more water in a glass-never stopped.

Then my sister reached into her handbag, produced two shiny iPads, and handed one to each child. Suddenly, the two were quiet. They sat playing games and watching videos, and we continued with our conversation.

After our meal, as my sister stuffed the iPads back into her bag, she said, “I don’t want to give them the iPads at the dinner table, but if they keep them occupied for an hour so we can eat in peace, I often just hand them over. I’m afraid it’s bad for them. I do worry that it makes them think it’s OK to use electronics at the dinner table in the future.”

Dr. Gary Small, director of the Longevity Center at the University of California, Los Angeles says that the brain is highly sensitive to stimuli (刺激物), like iPads and smartphone screens, and if people spend too much time on one technology, and less time interacting with people like parents at the dinner table, that could prevent the development of certain communication skills.

“Conversations with each other are the way children learn to have conversations with themselves, and learn how to be alone,” said Sherry Turkle, a professor of science, technology and society at the Massachusetts Institute of Technology. She fears that children who do not learn real interactions, which often have imperfections, will come to know a world where perfect, shiny screens give them a false sense of intimacy (亲密) without risk. However, they need to be able to gather themselves and know who they are. So someday they can form a relationship with another person without a panic of being alone. “If you don’t teach your children to be alone, they’ll only know how to be lonely,” she said.