It is quite reasonable to blame traffic jams, the cost of gas and the great speed of modern life, but manners on the road are becoming horrible. Everybody knows that the nicest men would become fierce tigers behind the wheel. It is all right to have a tiger in a cage, but to have one in the driver's seat is another matter.

    Road politeness is not only good manners, but a good sense. It takes the most cool-headed drivers great patience to give up the desire to beat back when forced to face rude driving. On the other hand, a little politeness goes a long way towards reducing the possibility of quarreling and fighting. A friendly nod or a wave of thanks in answer to an act of politeness helps to create an atmosphere of good will and becomes so necessary in modern traffic conditions. But such behavior of politeness is by no means enough. Many drivers nowadays don't even seem able to recognize politeness when they see it.

    However, misplaced politeness can also be dangerous. A typical example is the driver who waves a child crossing the street at a wrong place into the path of oncoming cars that may not be able to stop in time. The same goes for encouraging old ladies to cross the road wherever and whenever they want to.

An experienced driver, whose manners are faultless, told me it would help if drivers learnt to correctly join in a traffic stream without causing total blockages that give rise to unpleasant feelings. Unfortunately, modern drivers can't even learn to drive, let alone master the roadmanship (公路驾车技能). Years ago, experts warned us that the fast increase of the car ownership would demand more give-and-take (互谅互让) from all road users. It is high time for all of us to take this message to heart.

    When Hai started college, he weighed over 250 pounds Healthy food choices were difficult for him, and he was emotionally distraught (忧心忡忡). However, when he left home for college, he was able for the first time to start taking his life and weight into his own hands.

    He started by shopping at a local farmers' market, an experience that inspired him profoundly. The idea that a farmer's market represents local, sustainable, healthy food with a human connection where you can interact with the people that grow your produce was extremely appealing to him, and he began to think about the food that people at his university were eating. From what he saw at farmers' markets, Hai realized that dining hall food was not “real” food.A lot of it is frozen or processed, and has unhealthy additives. His ideas continued to develop as he started taking classes about food sustainability at university, and after the summer of 2014 during which he cooperated with other students9 he launched into his senior year at the University of California full force with the Real Food Challenge (RFC) campaign, a project he co-founded that aims to reinvest university spending in food that is “real”: ecologically-sound, community-based, humane, and fair; as opposed to those traditional purchases with those unhealthy additives and processed products.

    Not only has Hai started a movement of change across the university dining system, but he has also grown extremely as an individual，now with strong leadership abilities and great vision. In addition, after he started learning about food sustainability and taking action at university, Hai has lost over 100 pounds, and has been able to start enjoying activities such as backpacking and swimming that were not a possibility for him previously. He is confident instead of distraught now.

    How does an ecosystem（生态系统）work? What makes the populations of different species the way they are? Why are there so many flies and so few wolves? To find an answer, scientists have built mathematical models of food webs, noting who eats whom and how much each one eats.

    With such models, scientists have found out some key principles operating in food webs. Most food webs, for instance, consist of many weak links rather than a few strong ones. When a predator（掠食动物）always eats huge numbers of a single prey（猎物）, the two species are strongly linked; when a predator lives on various species, they are weakly linked. Food webs may be dominated by many weak links because that arrangement is more stable over the long term. If a predator can eat several species, it can survive the extinction（灭绝）of one of them. And if a predator can move on to another species that is easier to find when a prey species becomes rare, the switch allows the original prey to recover. The weak links may thus keep species from driving one another to extinction.

Mathematical models have also revealed that food webs may be unstable, where small changes of top predators can lead to big effects throughout entire ecosystems. In the 1960s, scientists proposed that predators at the top of a food web had a surprising amount of control over the size of populations of other species—including species they did not directly attack.

    And unplanned human activities have proved the idea of top-down control by top predators to be true. In the ocean, we fished for top predators such as cod on an industrial scale, while on land, we killed off large predators such as wolves. These actions have greatly affected the ecological balance.

    Scientists have built an early-warning system based on mathematical models. Ideally, the system would tell us when to adapt human activities that are pushing an ecosystem toward a breakdown or would even allow us to pull an ecosystem back from the borderline. Prevention is key, scientists says because once ecosystems pass their tipping point（临界点）, it is remarkably difficult for them to return.

    When my father married my mother in 1943, he gave my mother a 1937 crown coin and told her to keep it in the back of her purse and not to spend it. This would mean that she always felt that she was protected and would always have money if she really needed it.

    When I was married in 1970, my husband, who had heard this story, obtained a 1937 crown coin for me and I have always kept it in my wallet, and I have always had enough for my needs.

    A friend recently fell on hard times, partly through external (外部的) circumstances and partly through poor planning. Friends and I have loaned her money, paid her bills, given her food, and even tried to teach her budget techniques, but none of them has been a solution. She has just slipped deeper and deeper into financial trouble and depression.

    Last week she looked pale and unwell, very depressed and hopeless, very sad for a friend to see and I then thought about how the crown coin, a physical reminder of another's care and love had protected me, so I went to the bank for a $ 100 dollar-bill.

    I told my friend the story and asked her to keep the $ 100 in the back of her wallet. It turned out that she didn't have a wallet, so she put the money in a little pencil case where she kept her coins. She immediately felt better—"I feel rich, and thank you for being a good friend," she said, and we were both a bit teary.

    I went home and remembered a little wallet I had that I'd never used, and thought, "I'll give that to my friend." I opened it, and inside, found $ 100.

    The world's richest man might seem to have it all, but Bill Gates has one regret. The self-made billionaire said he felt stupid for not knowing any foreign languages.

    Speaking in his third Ask Me Anything question-and-answer session for online forum Reddit (红迪网), the Microsoft founder said that he wished he spoke French, Arabic or Chinese.

    He said: "I took Latin and Greek in high school and got A's and I guess it helps my vocabulary. I keep hoping to get time to study one of these—probably French because it is the easiest. I did Duolingo for a while but didn't keep it up."

    Gates, who is worth $79.3 billion, praised Facebook founder Mark Zuckerberg for surprising an audience in Beijing when he spoke fluent Chinese. "Mark Zuckerberg amazingly learned Chinese and did a Q&A with Chinese students—unbelievable, isn't it?" he said

    This isn't the first time for Gates to admit his regret over language. He also showed his habits at home and personal insights.

    Last February, Gates said he likes to do the dishes himself—to his own special standards every night and also told the interviewer that his wife, Melinda, would likely want Samuel L. Jackson to play her husband in a biopic (传记片).

    He also admitted that he would pick up a $100 bill if he found it on the street.

    As he took the top spot on Forbes (福布斯) 28th Annual Billionaires list last year for the fourth time, he said he is pretty basic when it comes to spending on clothes and food, but that he enjoys investing in shoes andracquets (球拍) when he plays tennis.

    When asked a life lesson he had to learn the hard way, the billionaire said staying up too late is a habit he is still trying to break. "Don't stay up too late even if the book is really exciting. You will regret it in the morning. Pam still working on this problem." he said.

    It was a normal school day for senior Solymar Solis until an unexpected visitor arrived. Her dad, Sgt. Carlos Solis Melendez, surprised her by coming home early from Kuwait and visiting her unannounced at Spring Valley High School in South Carolina.

    After serving in Kuwait for nine months, Melendez returned home a week earlier than his daughter expected. He held balloons and flowers in a classroom as he sat at a student's desk to blend in with the crowd. "It came across my mind like, ‘How is she going to react?" he recalled the heartwarming moment. "Is she going to be happy and run to me and hug me, or cry? That was all going on through my mind."

    As unsuspecting Solymar entered the classroom, she was soon overcome with emotion, immediately bursting into tears and covering her mouth. She didn't talk. She was just crying. She was overwhelmed with everything. She thought it was a dream.

    Melendez was a single parent so while he was deployed (调动), he got his sister to live with his daughter. When he was coming back and talking to his sister, both of them came to the conclusion that they should do something special for his daughter. Melendez and his sister got in touch with the school, and they planned this whole being-in-the-classroom thing, and it turned out perfect.

    The two are very much looking forward to some good daddy-daughter time now that he's home. "It means everything," Melendez said of being able to surprise his daughter this way. "After all the sacrifices she's made, she deserves all the special arrangements and special occasions and celebrations. I'll do anything for my daughter. I believe I'm doing good parenting."