As they migrate(迁移), butterflies and moths(飞蛾) choose the winds they want to fly with, and they change their body positions if they start floating in the wrong direction. This new finding suggests that insects may employ some of the same methods that birds use for traveling long distances. Scientists have long thought that insects were simply at the mercy of the wind.

    Fascinating as their skills of flight are, migrating behavior has been difficult to study in insects because many long distant trips happen thousands of feet above ground. Only recently have scientists developed technologies that can detect such little creatures at such great heights.

    To their surprise, though, the insects weren't passive but active travelers on the winds. In autumn, for example, most light winds blew from the east, but the insects somehow sought out ones that carried them south and they positioned themselves to navigate(导航) directly to their wintering homes.

    Even in the spring, when most winds flowed northward, the insects didn't always go with the flow. If breezes weren't blowing in the exact direction they wanted to go, the insects changed their body positions to compensate(抵消). Many migrating birds do the same thing.

    The study also found butterflies and moths actively flew within the air streams that pushed them along. By adding flight speeds to wind speeds, the scientists calculated that butterflies and moths can travel as fast as 100 kilometers an hour. The findings may have real-world applications.

    With climate warming, migrating insects are growing in number. Knowing how and when these pests move could help when farmers decide when to spray their crops.

The Secret of a Long Life

    I am Peter Brown. I am a writer with an important magazine. The other day I saw a white-haired man sitting on the chair in front of his house. I could see the wrinkles (皱纹) in his face and neck, and his wrinkled hands. Articles on the secrets of living to an old age are always popular with our readers, so I decided to write a story and discover the secret of this man's long life. As I went near him, I said:

    “Sir, would it be okay if I talked with you for just a moment?”

    “Not at all. Actually, it would make me very happy. I get very bored sitting here, even for a short time. Until a little while ago, I lived a full and active life without a moment's rest.”

    “Well, they say that a lot of activities help one to live a long time.”

    “That's true, very true. I still feel very well, although my step has slowed down a little.”

    The conversation continued in that way for a while. Although I tried to be very thoughtful about getting information from older people, it seemed to me that it would now be all right to begin to ask some polite questions.

    “Would it be okay if I smoked?”

    “Not at all.”

    “I'd offer you one, but I suppose you probably don't smoke, or drink, or…”

    “You're wrong! I've always smoked a great deal. And until a little while ago, I went dancing every night. And as for alcoholic drinks ...”

    “Do you mean to say that you've done these things all your life?”

    “Of course. Why does that surprise you so much?”

    “I've always been told that doing those things is bad for the health.”

    “Nonsense!”

    “I suppose that you have another secret ... a lot of fruit... vegetables ... a lot of exercise in the fresh air…”

    “Don't be silly! I hate exercise in the fresh air, and I don't like any kind of vegetable.”

    “This is unbelievable!”

    “What do you mean, unbelievable? What are you talking about?”

    “It's just that I can't understand how you've been able to live like that and to have lasted so long. Tell me, how old are you?”

    “Me? I'm twenty-eight. Why?”

    I was in the middle of coding a web page when my wife emailed me these questions: Ever wonder what it would be like to have the face, the brains, the personality and the body? What it would be like to have everyone stop when you walk in a room? What it would be like to be able to get anything or anyone you want? I stopped for a moment and thought about it because my wife wouldn't email me this unless something had driven her to do so. I emailed her back with what I thought was a pretty good answer. Here is what I wrote her back.

    Yes, I had thought many times about what it would be like to be one of the beautiful people. To be able to take your breath away when I walked into a room, or to be the life of the party and have everyone fawning (奉承) over me as I wore only the finest clothes and sported the perfect body? But then I always came back to the realization that a lifestyle like that is so fragile. As you get older, your body changes; as you get older, the money changes. Your body never looks the same, the clothes become more and more expensive to maintain. And once you have crossed the line, suddenly you are out. The next fresh face comes in and you are quickly forgotten.

    All through growing up I was never an attractive person. I was overweight and picked on. But that didn't stop me from being a nice person — a good, clean, funny and helpful person. I was the person who you came to when you needed a friend after a breakup. I was the one you came to when you needed a joke to brighten up your day. And in the long run, I will be the one you remember, not the new face, or the fresh style.

    In closing, I would like to say that we, as a people, have developed into looking (or things that are bigger and better instead of what will last. I don't know about you, but I will remember the friend who helped me when I was down, more than the hot girl I just saw walking down the street.

    I wish I could teach the world some more jokes.

    Can small, organic agriculture really feed the world? Won't we need science to produce enough food as the world population is growing to 9 billion by 2050? The answer to both questions is YES—but that science may look different than you think.

    We've been told that the only way we'll be able to feed the growing population is through the science of GM(转基因) crops and chemicals. But the latest scientific studies are saying just the opposite. In study after study, the message about agriculture is: To feed the world, we need to support sustainable (可持续的) agriculture on different, local, family farms that work with nature.

    In 2008, an international study found that sustainable agriculture, not GM crops, shows more hope of ending hunger. The International Assessment of Agricultural Knowledge, Science, and Technology for Development (known as the IAASTD), calls for a change of the world's food and farming systems.

    The Assessment said that industrial agriculture has greatly destroyed the world's soils and other natural resources, and now is doing harm to water, energy, and weather safety. The report warns that expensive, short-term ways—including GM crops—are not likely to cut down long-term hunger, and could even make environmental and social problems worse in many places.

    A recent report by the UN Environment Program shows that food problems will become more serious because of environmental problems and strongly supports sustainable agriculture on small family farms. It also showed that a worldwide change to organics could actually increase the world's food production by as much as 50%—enough to feed a population of 9 billion people with the land we have now. GM crops, once popular, are now being questioned worldwide.

    Pangolins (穿山甲) are strange-looking creatures, covered with hard scales (鳞). They can roll up into a ball to protect themselves from enemies and have tongues that are longer than their bodies.

    Pangolins have recently become the focus of Chinese people. A screenshot (截屏) of a micro blog post showing some people eating pangolins at a feast spread. A few days later, people were angered again by pictures showing people eating protected animals, including pangolins.

    Yet this is only the tip of the iceberg. Many more pangolins have been hunted or killed. According to the International Union for Conservation of Nature (IUCN), more than 1 million of them have been killed or sold in the last 10 years. It also said that they are the most illegally traded mammals in the world. In September 2016, the IUCN added the pangolin to the world's "endangered animals list". They are now more endangered than pandas.

    A growing trade of their scales and meat is the main reason for their decline in numbers. Many people in Asia and Africa consider pangolin meat is delicious. Some people even think pangolin scales have medical qualities. However, their scales are made of keratin (角蛋白), the same material human fingernails are made of.

    Luckily, the situation is getting better. World Pangolin Day is on the third Saturday of February each year. It's a day to help people know more about pangolins. The government now stops anyone from buying and eating pangolins in China. Breaking this law is regarded as a crime. The trade of pangolins across the world is also not allowed, according to the Convention on Trade in Endangered Species of Wild Fauna and Flora.

    A Latin phrase beloved by every old-fashioned British schoolmaster was mens sana in corpora sano—a healthy mind in a healthy body. Greater physical activity is associated with better mental, as well as physical health. And it might also be linked to greater worker productivity, and thus faster economic growth. That is the conclusion of a new report from a European think tank — RAND.

    The RAND study looks at different measures: absenteeism (when workers take time off for illness) and presenteeism (when they turn up for work but are less productive because of sickness). The latter measure was self-reported by employees, who were asked whether their work was negatively affected by health issues. The survey suggests that between 3 and 4.5 working days each year are lost as a consequence of workers being physically inactive. This is between 1.3% and 2% of annual working time. Most of this was down to presenteeism.

    Another potential gain from improved fitness is reduced health-care costs. In America, where health care is often provided through employment-based systems, firms could benefit. RAND estimates that total American health savings could be $6bn a year by 2025. But the study's authors conclude that if people met certain exercise targets, global GDP could be around 0.17-0.24% higher by 2050. Nothing to laugh at in a world of slowing growth.

    How to encourage workers to become more active? Rewards are useful but only if they have conditions; giving all employees free gym membership does not seem to work. Another RAND Europe study examined an experiment in which workers were each given an Apple watch, payable in instalments (分期付款) at a discounted price—but only to those who agreed to have their physical activity monitored. Monthly repayments depended on how much exercise they took.

    The problem is that many people are too optimistic about their health, ignoring the risks they face. This means that participation in workplace exercise plans tends to be low, around 7% in the sample studied by RAND. Firms are not the only ones that can encourage a healthier lifestyle; friends and families are likely to be more important. But businesses can play a bigger role.

    If RAND is right, this may bring them financial benefits. Company taskmasters may yet grow fond of an adapted saying: mens sana in corporate sano.