The next time you go grocery shopping, try speaking to other customers. One summer day, I took a smile and a warm heart into a small store in Oregon and got far more than groceries.

    I love fresh produce(农产品) in the store, and not just for the amazing colors provided by summer's bounty (慷慨) or the chance to joy over new choices from other countries. It's also because I just love watching people pick their produce.

    The day I was there I found a sale on amazing cherry tomatoes—along with a woman in her late 70s. Despite the fact that we were strangers, we began to discuss apples. She noted a problem with the Pink Ladies. "They tasted like I was eating an unripe green apple from the tree," she said, twisting her face as if still tasting the sour apple.

    I wondered if this is something most of my generation can even remember doing. I surely do. I mentioned that I often could not resist the green yet tempting fruit swinging from an apple tree. This was the start for a series of discussions as we shopped-covering such topics as nutrition, new foods and the quality of produce.

    By this time a third woman had joined in our conversation. The three of us continued along, unexpected friends, chatting about family size and the troubles a mom might have serving healthful foods that please the whole family.

    Eventually we all went our separate ways, but in the dairy(奶制品) section I heard a small voice say, "I finally caught up with you." It was the first woman I'd talked to, extending a bag of apricots(杏) to me. "I don't know if your family will eat these," she added, "but they have a super deal on them."

    Again I was brought back to my childhood, when I also ate apricots straight from the tree. My mouth watered at the remembered flavor.

    The old lady didn't realize that she'd given me far more than produce. With that offering came a sense of community, a flashback to days when it was OK to talk to a stranger. She brought back memories of summer fruits right from the tree—and a feeling that somehow those apricots were a thank-you for sharing my time with her in a very unlikely place.

    “Heaven (天堂) is where the police are English, the cooks are French, the mechanics are German, the lovers are Italian and everything is organized by the Swiss. Hell (地狱) is where the police are German, the cooks are English, the mechanics are French, the lovers are Swiss, and everything is organized by the Italians.”

    Obviously the national stereotypes (模式化的思想) in this old joke are generalizations (普遍化), but such stereotypes are often said to “exist for a reason”. Is there actually a sliver (裂片) of truth in them? Not likely, an international research team now says.

    “National and cultural stereotypes do play an important role in how people see themselves and others, and being aware that these are not dependable is a useful thing,” said study author Robert McCrae of the National Institute on Aging. “These are in fact unfounded stereotypes. They don't come from looking around you,” McCrae said.

    If national stereotypes aren't rooted in real experiences, then where do they come from? One possibility is that they reflect national values, which may become known from historical events. For example, many historians have argued that the spirit of American individualism (个人主义) has its origins in the experiences of the pioneers on the Old West.

    Social scientists such as psychologist Richard Robins have given several other possible explanations for stereotypes and why they may be incorrect. Robins notes that some stereotypes may have been correct at one point in history and then remained unchanged while the culture changed.

    We may be “hard-wired”, to some degree, to keep incorrect stereotypes, since we are less likely to notice and remember information that is different from our stereotypes. Generally, according to Robins, when we meet people who are different from our stereotypes, we see them as unique individuals rather than typical national or cultural groups.

    When I was 3 years old, I was found to be deaf in my left ear and have a small problem in my right. Being hard of hearing has been difficult, but I've never lived in a state of self-hating sorrow.

    Imagine being able to shut out all sounds as you lay your head down to sleep by simply rolling over onto one side. That's my reality when I sleep on my “good ear”, and it even makes me feel like a superhero sometimes.

    People call my deaf side my “bad ear”, but when I wear my hearing aid, I have access to a range of features(特征)that some other deaf people don't.

    In cinemas, for example, with one click of a button I can enjoy a whole film as though it were whispered to me from the mouths of the actors.

    Having a hearing aid hasn't always felt good, however.

    On the first day I got my aid, when I was 8, I took it to school for show-and-tell. As I explained how it worked to my classmates, a boy yelled out, “Aren't those for old men?”

    At that moment, I felt different. It took a long time for me to get over that sense of being so unlike my peers(同龄人).

    But it's not just choolkids who can make us deaf and hard-of-hearing people feel like burdens(负担).

    Every video on social media that lacks subtitles, for example, means an entire community of deaf people is unable to enjoy it.

    Completely deaf people are excluded from enjoying many movies too, as subtitles in cinemas are almost impossible to find.

    And with hearing aids costing around $2,500 each, it can be hard for many people to afford to be able to listen to the things that others take for granted.

    As for me, I can listen to music, enjoy films, and catch conversations – I'm lucky.

I'm deaf, but I can still hear everything. I've been blessed with wonderful life experiences.

    Since English biologist Charles Darwin published On the Origin of Species in 1859, scientists have vastly improved their knowledge of natural history. However, a lot of information is still of the speculation, and scientists can still only make educated guesses at certain things.

    One subject that they guess about is why some 400 million years ago, animals in the sea developed limbs (肢) that allowed them to move onto and live on land.

    Recently, an idea that occurred to the US paleontologist (古生物学家) Alfred Romer a century ago became a hot topic once again.

    Romer thought that tidal (潮汐的) pools might have led to fish gaining limbs. Sea animals would have been forced into these pools by strong tides. Then, they would have been made either to adapt to their new environment close to land or die. The fittest among them grew to accomplish the transition (过渡) from sea to land.

    Romer called these earliest four-footed animals “tetrapods”. Science has always thought that this was a credible theory, but only recently has there been strong enough evidence to support it.

    Hannah Byrne is an oceanographer (海洋学家) at Uppsala University in Sweden. She announced at the 2018 Ocean Sciences Meeting in Oregon, US, that by using computer software, her team had managed to link Homer's theory to places where fossil deposits (沉积物) of the earliest tetrapods were found.

    According to the magazine Science, in 2014, Steven Balbus, a scientist at the University of Oxford in the UK, calculated that 400 million years ago, when the move from land to sea was achieved, tides were stronger than they are today. This is because the planet was 10 percent closer to the moon than it is now.

    The creatures stranded in the pools would have been under the pressure of “survival of the fittest”, explained Mattias Green, an ocean scientist at the UK's University of Bangor. As he told Science, “After a few days in these pools, you become food or you run out of food... the fish that had large limbs had an advantage because they could flip (翻转) themselves back in the water.”

    As is often the case, however, there are others who find the theory less convincing. Cambridge University's paleontologist Jennifer Clark, speaking to Nature magazine, seemed unconvinced. “It's only one of many ideas for the origin of land-based tetrapods, any or all of which may have been a part of the answer,” she said.

    It is obvious that all of our childhood memories are not accidental. When you are a child, every scent, every sound, every move, every toy, the first day of school, the first kiss, the first step… Everything together makes what is the personality of a man. All these are pieces of one whole entity.

    I was about 6 years old. My mom's best friend left to another town and asked my mom to stay at her place with me for two days in order to look after her two sons. One was a little older than I was, and the second boy appeared to be super grown-up, for he was already fourteen. I always enjoyed staying at their place.

    I remember the second day we were supposed to have the come-back party for my mom's friend at her place. I woke up. Mom went to work and reminded me to be nice and clean by the time she came back. I stayed with Tony, the older of the boys and suddenly somebody called him and though he was not permitted to leave me alone-he left. He said it would not be long. But it took him forever. I realized that I was alone. I could not come out of the house, so I opened the window. I was so desperate. So lonely. So betrayed. At that moment I pulled the curtain so strongly that I fell on the floor. And there I was standing-one little criminal-desperate to escape and knowing that I would be punished for destroying the curtain that was not even ours.

But then something changed. I stopped weeping. I looked around and realized that I was in a safe place, and that mom would come back and kiss me no matter what I had done.

    This was a moment of pure happiness, not the happiness of getting a new toy or a dog, or going to the party of your best friend. It was the moment of clarity for me-the first time in my life when I realized that I was happy to have my mom and that I was safe. My eyes saw the world in different shades that moment. And by the way-I was not punished for the curtain. I fell asleep on my mom's knees.

    A few weeks ago, I sat with a California farmer named Dave Ribeiro. I asked him what he wished to know about farmers. He smiled and said, "That we walk among you. We look like you and talk like you. We have advanced degrees and hobbies, just like you."

    Take Dave for example: He's a young man with a music degree. And if you walked past him on the street, you'd never think, "There goes a farmer."

    Is someone like Dave who you picture when you think of a farmer? Probably not. I think that most people would picture a man in his overalls(工作服). I can tell you, that does not represent Dave or any of the many other farmers I have gotten to know.

    Not only do we have to throw out our previous impression of farmers, but farming as a whole doesn't look much like it used to either. We recently sent a team out to see what modern farming looks like, and they found farmers to be completely different from our usual ideas about them and also came across them in some unexpected places.

    In a parking lot in a neighborhood of Brooklyn, they met a new crop of young farmers who were trying to bring fresh greens closer to eaters in the city by growing them in high-tech indoor vertical(垂直的) farms. In a Florida field under the fight path of an airport, they discovered farmers with university degrees growing plants that might someday fuel our cars. And in a modern farm in California, they observed how farmers were using technology to take the best possible care of their animals.

    These farmers all spend their days in very different ways—none of them looks like the previous farmer we have in our mind—but they're all working on new ways to feed our planet. Not only do we need to change our idea of what farming looks like, but we also need to change our view of where solutions can come from. Feeding all of us is going to take all of us working together.