Mail lay scattered across the kitchen table. I couldn't put off sorting through it any longer. I checked the envelopes, putting aside the ones addressed to my husband.

    It had been over three years since Bob had died. To friends and family it looked like I had moved past the worst of my sorrow. I took care of my house, socialized and kept up with community. On the outside everything appeared to be normal. But inside I was anything but I worried I would never get better, never be myself again. They say sorrow has no set time limit, but I was so tired of feeling empty and hopeless. My sorrow was sharp and fresh as ever. It was like a wall of pressure in my chest, pressing my heart.

    I picked up a piece of Bob's mail and held it out to tear in half, but stopped myself from cutting up the envelope. The letter was from an organization that funded a Haitian orphanage called My Father's House. Its founder, Carol Hawthorne, had given a presentation at our church. Bob and I had donated, and Bob ended up on the mailing list to receive the newsletter (通讯) with updates on the children.

    I hadn't read one since Bob died. But just three months before, in January 2012, the country had been hit by a terrible earthquake. In my depressed state, it hadn't even occurred to me to wonder whether the orphanage had survived. I opened the newsletter and was surprised to find out that My Father's House was still standing. Of course now it was more crowded than ever. At the bottom of the page was an announcement about an upcoming trip to visit the orphanage in person. “I should go.” The thought wouldn't leave me. I contacted Carol Hawthorne.“What would I do if I go?” I asked.“Build houses?”

    “The Haitian people there are eager to work and they know what they're doing,” said Carol. “What they need are raw materials, and we provide them. We also visit with the children. We go to clinics and schools, pass out supplies. You'll be very busy, I promise!” I reserved a seat but didn't mention it to any of my friends. Just a few weeks later, I was at the airport with seven strangers, waiting to board a plane to Haiti. Even after takeoff I wasn't really sure of what I was doing.

    In Haiti we were met by Pastor Ronald Lefranc, the director of My Father's House. We piled into an old school bus and drove over uneven roads full of stones and mud. We passed women shaking under the weight of huge water buckets balanced on their heads. Piles of rubbish scattered across the landscape, and the land was covered with broken tents. Finally we pulled up to the orphanage. A crowd of children—52 in all—rushed up to greet us. I couldn't understand the words of the song they sang in Creole, but with the smiles on their faces I didn't need to. Each child planted a big kiss on my cheek.

    Carol and Pastor Ronald led us into the main building. “What are those over there?” I asked, pointing to a collection of thin tents. “Is there not enough room in the building for all the children?”

    “We have the room,” said Pastor Ronald. “But many of these children came here after the earthquake. They still don't feel safe sleeping under a roof.”

    There was no sign of fear in the playroom inside. I played dolls and other games. Children I'd just met presented me with pictures they'd drawn and letters written in Creole. In the evening the children gathered in the dining room. They took turns reading aloud and then they all joined in song. The words were strange, but the tune sounded familiar.

    They'd lost so much, yet were so joyful. In the evening the children gathered in the dining room. One of the older children stood up to speak and then they all joined in song. The words were strange, but the tune sounded familiar. The children settled down. In the silence, a quiet noise began.

    Researchers at the University of Kansas say that people can accurately judge 90 percent of a stranger's personality simply by looking at the person's shoes. “Shoes convey useful information about their wearers”, the authors wrote in the new study published in the Journal of Research in Personality．

    Lead researcher Omri Gillath said the judgments were based on the style, cost, color and condition of someone's shoes. In the study, 63 University of Kansas researchers looked at pictures showing 208 different pairs of shoes worn by the study's participants. Volunteers in the study were photographed in their most commonly worn shoes, and then filled out a personality questionnaire.

    Some of the results were expected: People with higher incomes most commonly wore expensive shoes, and flashier shoes were typically worn by outgoing people. However，some of the more specific results are strange enough. For example, “practical and functional ''shoes were generally worn by more “pleasant" people, while ankle boots were more linked with “aggressive” personalities. The strangest of all may be that those who wore “uncomfortable looking” shoes tend to have “calm” personalities. And if you have several pairs of new shoes or take extreme care of them, you may suffer from “attachment anxiety", spending lots of time worrying about what other people think of your appearance. There was even a political calculation in the mix with more liberal (主张变革的) types wearing “shabbier and less expensive” shoes.

    The researchers noted that some people will choose shoe styles to mask their actual personalities, but researchers noted that volunteers were also likely to be unaware that their footwear choices were showing the deep side of their personalities.

    When I spent the summer with my grandmother, she always set me down to the general store with a list. Behind the counter was a lady like no one I'd ever seen.

    “Excuse me,” I said. She looked up and said, “I'm Miss Bee.”

    “I need to get these.” I said, holding up my list. “So? Go get them. ” Miss Bee pointed to a sign. “There's no one here except you and me and I'm not your servant, so get yourself a basket from that pile.”

    I visited Miss Bee twice a week that summer. Sometimes she shortchanged me. Other times she overcharged. Going to the store was like going into battle. All summer long she found ways to trick me. No sooner had I learned how to pronounce “bicarbonate of soda” and memorized its location on the shelves than she made me hunt for it all over again. But by summer's end the shopping trip that had once taken me an hour was done in 15 minutes. The morning I was to return home, I stopped in to get some run.

    “All right, little girl,” she said. “What did you learn this summer?” “That you're a meanie!” I replied. Miss Bee just laughed and said, “I know what you think of me. Well, I don't care! My job is to teach every child I meet life lessons. When you get older you'll be glad!” Glad I met Miss Bee? Ha! The idea was absurd.

    Until one day my daughter came to me with homework troubles. “It's too hard,” she said. “Could you finish my math problems for me?”

    “If I do it for you, how will you ever learn to do it yourself?” I said. Suddenly, I was back at that general store where I had learned the hard way to add up my bill by myself. Had I ever been overcharged since?

    AlphaGo is a computer program that plays the board game Go.

    In March, 2016, the pride of humankind was crushed (粉碎) by a computer. Google's AlphaGo defeated the South Korean grandmaster (围棋大师) Lee Sedol four games to one, as the world looked on with shock and awe (敬畏). Artificial intelligence (AI, 人工智能) had suddenly reached a new and unexpected height.

    But as smart as AlphaGo is, it's no longer the best Go “player” in the world. Google's artificial intelligence group, DeepMind, has created the next generation of its Go-playing program, called AlphaGo Zero. The new AI program is unique in the way it learned to play Go. Instead of learning from thousands of human matches, as its predecessor (前任) did, AlphaGo Zero mastered Go in just two days without any human knowledge of the game and defeated AlphaGo by day three, reported The Guardian. It then went on to defeat AlphaGo 100 games to zero.

    To learn how to play Go, AlphaGo Zero played millions of matches against itself using only the basic rules of the game to rapidly create its own knowledge of it. Like the previous version, it used “reinforcement (增强) learning to become its own teacher,” according to DeepMind's website.

    “It's more powerful than previous approaches,” David Silver, AlphaGo's lead researcher, told The Guardian, “because by not using human data, or human expertise in any fashion, we've removed the constraints (约束) of human knowledge and it is able to create knowledge itself.”

    AlphaGo Zero's approach to self-learning is a significant advancement in AI that could be applied to help solve some of the world's biggest problems, according to a recent research report published in the journal Nature. For example, DeepMind co-founder Demis Hassabis argues that AlphaGo Zero could probably find cures for a number of serious diseases within weeks, according to The Telegraph. Indeed, the AI is now being used to study protein folding, which is connected to diseases such as Parkinson's and Alzheimer's.

    So now that AI has exceeded (超过) the bounds of human knowledge, perhaps the question is not about what AI can learn from humans, but what humans can learn from AI. We can only wait and see.

    Recently a new study has been carried out. It shows students who write notes by hand during lectures perform better on exams than those who use laptops.

    Students are increasingly using laptops for note-taking because of speed and legibility (清晰度). But the research has found laptop users are less able to remember and apply the concepts they have been taught.

    Researchers performed experiments that aimed to find out whether using a laptop increased the tendency to make notes “mindlessly” by taking down word for word what the professors said.

    In the first experiment, students were given either a laptop or pen and paper. They listened to the same lectures and were told to use their usual note-taking skills. Thirty minutes after the talk, they were examined on their ability to remember facts and on how well they understood concepts.

    The researchers found that laptop users took twice as many notes as those who wrote by hand. However, the typists performed worse at remembering and applying the concepts. Both groups scored similarly when it came to memorizing facts.

    The researchers' report said, “While more notes are beneficial, if the notes are taken mindlessly, as is more likely the case on a laptop, the benefit disappears.”

    In another experiment aimed at testing long-term memory, students took notes as before but were tested a week after the lecture. This time, the students who wrote notes by hand performed significantly better on the exam.

    These two experiments suggest that handwritten notes are not only better for immediate learning and understanding, but that they also lead to superior revision in the future.

    Over the past few years, smart home tech has become more and more accessible and it's increasingly easy to find that you've bought a product that includes smart home features. So what does a modem smart home look like, and how can you start building one? You could get to start making your home smarter by the following gadgets.

    Ecobee 4

    Measuring both occupancy and temperature, its sensors signal your Ecobee to automatically switch to the right mode.

    It only takes about 30 minutes, thanks to an easy-to-follow installation guide and an in-app step-by-step walkthrough.

    Easily adjust temperature using your voice with built-in Alexa or from wherever you are using your mobile devices.

    Amazon Smart Plug

    Amazon Smart Plug works with Alexa to add voice control.

    Schedule lights, fans, and appliances to turn on and off automatically, or control them remotely when you're away.

    It's simple to set up and use. Plug in, open Alexa app, and start using your voice.

    The Philips Hue White Smart Bulb

    It works with Amazon Alexa to support dimming through voice control.

    Schedule your own custom lighting scenes. Set the smart bulbs to turn on and off at a pre-set time.

    To install, simply screw (拧) the smart bulbs into your desired light location.

    Control smart-bulb-equipped lamps and overhead lights via the Philips Hue App.

    August Smart Lock Pro

    It works with Alexa for voice control (Alexa device sold separately).

    Control keyless access. It locks automatically behind you, and unlocks as you approach.

    Install in about 10 minutes with just a screwdriver (螺丝刀) .