With the development of science and technology, new inventions, especially new electronic products, have made people's lives easy and convenient. But as the saying puts: A coin has two sides.

    One day, I was walking in the park with a friend and his cell phone rang, interrupting our conversation. There we were, walking and talking on a beautiful sunny day and…I became invisible, absent from the conversation.

    The telephone used to connect you to the absent. Now it makes people sitting next to you feel absent. Why is it that the more connected we get, the more disconnected I feel? Every advance in communications technology is a tragedy to the closeness of human interaction. With email and instant messaging over the Internet, we can now communicate without seeing or talking to one another. With voice mail, you can conduct entire conversations without ever reaching anyone. If my mom has a question, I just leave the answer on her machine.

    As almost every contact we can imagine between human beings gets automated, the alienation(疏远) index goes up. You can't even call a person to get the phone number of another person any more. Directory assistance is almost always fully automated.

    Pumping petrol at the station? Why say good morning to the attendant when you can swipe(刷)your credit card at the pump and save yourself the bother of human contact?

    Making a deposit at the bank? Why talk to a teller who might live in the neighborhood when you can just insert your card into ATM?

    Pretty soon you won't have the burden of making eye contact at the grocery shop. Some supermarket chains are using a self-scanner so you can check yourself out, avoiding those check-out people who look at you and ask how you are doing.

    I am not against modern technology. I own a cell phone, an ATM card, a voice mail system, and an email account. Giving them up isn't wise…they're a great help to us. It's some of their possible consequences that make me feel uneasy.

    More and more, I find myself hiding behind e-mail to do a job meant for conversation. Or being relieved that voice mail picked up a call because I didn't really have time to talk. The communications industry devoted to helping me keep in touch is making me lonelier.

    So I've put myself on technology restriction: no instant messaging, with people who live near me，no cell phoning in the presence of friends, no letting the voice mail pick up when I'm at home.

    An international team of researchers from the University of Oxford have found that the way people use the Internet is closely tied to the seasonal movements in the natural world. Their online species searches follow the patterns of seasonal animal migrations (迁徙).

    Migratory birds (候鸟) flood back to where they reproduce every spring. That migratory behavior is accompanied by some human behavior. "In English-language Wikipedia (维基百科), the online searches for migratory species tend to increase in spring when those birds arrive in the United States," said the lead author John Mittermeier.

    And not just birds. Mittermeier and his team surveyed nearly 2.5 billion Wikipedia search records, for 32,000 species, across 245 languages. They also saw variable search rates for insects, horsetails and flowering plants. Seasonal trends seemed to be widespread in Wikipedia behavior for many species of plants and animals.

    This finding suggests new ways to monitor changes in the world's biological diversity. It also shows new ways to see how much people care about nature, and which species and areas might be the most effective targets for conservation.

    Mittermeier is encouraged by the search results. He commented, "I think there's a concern among conservationists (生态环境保护者) that people are losing touch with the natural world and that they're not interacting with native species anymore. And so in that sense, it was really exciting and quite unexpected for me to see people's Wikipedia interest closely related to changes in nature."

    Richard Grenyer, Associate Professor from the University of Oxford, says search data is useful to conservation biologists, "By using these big data approaches, we can direct our attention towards the difficult questions in modern conservation: which species and areas are changing, and where are the people who care the most and can do the most to help."

    It seems we're always being told to get more sleep. Studies suggest spending less time on sleep can lead to obesity(肥胖) and even cancer. You might even find yourself with a head full of false memories. But rarely does science explore the dark side of sleeping too much. That's because few of us in today's busy world have the luck of exploring that option.

    In an August 2018 study, published in the Journal of the American Heart Association, researchers researched the sleep patterns of those "fortunate" few and found they may not be so lucky after all. In fact, they found people who get more than eight hours of sleep have greater health risk compared to those who sleep together less than seven hours. What's more, sleep-aholics-those who manage to get 10 hours a night-stand a 30 percent higher chance of dying compared to the seven-hour crowd.

    The wide-ranging global study involved(涉及) more than three million people who self-reported on their sleep habits and came to an eye-opening conclusion: If you tend to sleep a lot, you may want to buy an alarm clock. As with all things in life, sleep is best taken in moderation(适度).

    You may be thinking: What if I only sleep in on Saturday and Sunday, am I still at risk? The answer is yes, according to a 2019 study published in Current Biology.  Researchers discovered that even if a person sleeps more than seven hours on the weekends but still sleeps less than that on weeknights, they are at risk of gaining weight and developing sensitivity to insulin, which controls the level of sugar in blood.

    For the study, 36 participants were divided into three groups that each had a different sleep schedule: nine hours every night, five hours every night, and five hours from Monday to Friday and sleeping much on weekends. People who get too much sleep tend to feel tired and lack energy. Also, both sleep-deprived(睡眠不足的) groups consume more food and gain weight.

People have long watched moths （飞蛾） and other flying insects flock to streetlamps, lights and flames. These insects appear attracted by the light. But a new study suggests they may just lose track of which way is up.

Previous theories say light probably blinds flying insects so that they get trapped by the light, or maybe they interpret light at night as a place to fly for a quick escape. Now the new study suggests flying insects instead turn their backs to the sky's light to keep their feet pointing toward the ground. Insects naturally turn their backs toward light. But when that light is from an artificial source, it may affect their sense of direction, leading to them flying in circles or diving toward the ground.

At a field station in Costa Rica, Samuel Fabian, an entomologist from Imperial College London in England and his teammates set up hanging and standing lights, and then used high-speed cameras to track wild, flying insects including moths and flies. Some circled the lights endlessly, and others flew sharply upward, losing speed until they couldn't fly any higher. When the light source pointed up, some insects turned around and headed for the ground. During the flight, the insects always kept the lights at their back even if they'd end up crashing. Crash landings were common when the team lit up a white sheet on the floor. But not when a white sheet—stretched into a height above the floor—was bathed in diffuse （漫射） light, much as the sky would be, insects flew through the area without getting trapped by the light.

The team also observed some species in a lab. Moths and dragonflies generally behaved like the wild insects, and they kept the light at their backs. However, in the lab, fruit flies, like oleander hawk moths—which can fly in the dark—could fly over LED lights without being thrown off course. In the wild, though, the moths still crashed. Maybe this is because, Fabian says, the insects can sometimes control their response to light, or over time, they might learn to avoid artificial light.

I just returned from India. While driving home from the airport, I was amazed by how everything in American streets 1 those in Delhi, a city in northern India. "You can eat off the street here!" I said. My family looked at me 2 I had gotten off a spaceship rather than a plane.

During the two years I was away, my friends and family 3 sending texts to each other by phone. After I came back, my phone was no longer 4 as before, just lighting up with the "ding" sound of a text, and I felt very 5 . I chose to talk to my friends instead of texting them. I asked my friends for their 6 as I made an effort to7 with them and rebuild our friendships.

While I was on my 8 trips, most of my friends had moved on with their 9 . We felt disconnected from each other's experiences. Just as 10 would always be part of my life, I understood that raising a family would always be part of theirs. I told them sometimes I felt 11 because I had been away and wasn't there for their 12 events.

Expats（侨民）in Laos say that sometimes, if you stay abroad too long, you become a permanent 13 . never quite making it as a local, and never feeling 14 in your home country. I 15 . If you always travel with a heart beating for your beloved ones, no matter how long you have been abroad, you will find satisfaction at home.