Wetlands are ecosystems found in low, flat areas. Often they border ponds, rivers, lakes, and oceans. Wetlands include marshes, swamps, and bogs.

    No trees grow in a marsh, but there are lots of grassy plants. Ducks, turtles, and many different bugs (虫子) live there, too. Florida has the world's biggest freshwater marsh. The Everglades covers 4,000 square miles. The Everglades is not entirely fresh water, however. Near the sea the fresh water and salt water mix. Some plants and animals can live only in this brackish water.

    Saltwater marshes lie along the East Coast and the Gulf of Mexico. During high tide these marshes are under water. During low tide these marshes can be seen. The water rushes out, carrying bits of plants, dead animals, and minerals necessary for sea animals. Many plants and animals depend upon this ever-changing environment.

    Swamps are forested wetlands. Like marshes, they are often found near rivers or lakes and have mineral soil that drain very slowly. Unlike marshes, they have trees and bushes. Swamps have trees that grow with their roots underwater. But the trees will die if their roots stay underwater too long. Animals such as water snakes and frogs live in swamps.

    Bogs have damp, soft soil. So many dead plants have piled up that there is no longer any standing water. This rotting plant matter turns into peat (泥炭). In Ireland and Scotland peat is dried and burned to heat homes. Bog soil is useful for growing wild rice. Lots of insects live there.

    Most people do not find wetlands beautiful. But wetlands are important. Marshes and swamps store water, thus reducing the flooding a heavy rain can cause. About one-third of all of America's endangered plants and animals live in wetlands. Now laws protect some wetlands. More than a dozen wetlands in the US are refuges (保护区) and wildlife preserves.

    Being sociable looks like a good way to add years to your life. Relationships with family, friends, neighbours, even pets, will all do the trick, but the biggest longevity(长寿) boost seems to come from marriage or an equivalent relationship. The effect was first noted in 1858 by William Farr, who wrote that widows and widowers(鳏夫) were at a much higher risk of dying than their married peers. Studies since then suggest that marriage could add as much as seven years to a man's life and two to a woman's. The effect holds for all causes of death, whether illness, accident or self-harm.

    Even if the odds are stacked against you (the conditions are not favourable), marriage can more than compensate. Linda Waite of the University of Chicago has found that a married older man with heart disease can expect to live nearly four years longer than an unmarried man with a healthy heart. Likewise, a married man who smokes more than a pack a day is likely to live as long as a divorced man who doesn't smoke. There's a flip side, however, as partners are more likely to become ill or die in the couple of years following their spouse's death, and caring for a spouse with mental disorder can leave you with some of the same severe problems. Even so, the odds favour marriage. In a 30-year study of more than 10,000 people, Nicholas Christakis of Harvard Medical School describes how all kinds of social networks have similar effects.

    So how does it work? The effects are complex, affected by socio-economic factors, health-service provision, emotional support and other more physiological mechanisms(机制). For example, social contact can boost development of the brain and immune system, leading to better health and less chance of depression later in life. People in supportive relationships may handle stress better. Then there are the psychological benefits of a supportive partner.

    A life partner, children and good friends are all recommended if you aim to live to 100.The best social network is still being mapped out, but Christakis says: “People are interconnected, so their health is interconnected.”

    Luo Jingyu, 19, has four years of experience of running business. He is also a freshman in the arts department of Hubei University.

    Luo Jingyu is from an ordinary family. He said, "My parents told me if I wanted something I should make an effort to get it, so I earned pocket money by doing housework when I was little." The dream of running his own business grew in his heart. He said, "I want to be a successful person, like Alibaba's Ma Yun."

    When Luo was a junior student, he had the idea of selling lanterns when he saw many people flying Chinese lanterns in a square. Luo bought some lanterns from a store, but the sales were not as good as he had expected. Then he found another way to do business. He bought lanterns on the Internet at a very low price. Finally he easily made 5,000 yuan in two days.

    With a happy beginning, Luo planned to open a dress shop. "My parents didn't support me opening a dress shop, so I had to borrow 120,000 yuan for it." Although he did market research before starting, the business wasn't very good because his taste in fashion wasn't accepted by customers. The shop eventually closed down after half a year.

    After experiencing a big loss, he decided to do something he was familiar with—selling painting tools. As a fine arts student, he knew the market. He convinced his friends to invest one million yuan in his shop. With a good business mind and a lot of effort, the sales of the shop reached six million yuan in a year.

    Even though Luo is rich, he uses a cheap cell phone and does not wear luxury clothes. He has a simple lifestyle. "It isn't easy to make money, so money should be used on something worthwhile," he said.

By now you've probably heard about the "you're not special" speech, when English teacher David McCullough told graduating seniors at Wellesley High School: "Do not get the idea you're anything special, because you're not." Mothers and fathers present at the ceremony — and a whole lot of other parents across the Internet — took issue with McCullough's ego-puncturing words. But lost in the uproar was something we really should be taking to heart: our young people actually have no idea whether they're particularly talented or accomplished or not. In our eagerness to elevate their self-esteem, we forgot to teach them how to realistically assess their own abilities, a crucial requirement for getting better at anything from math to music to sports. In fact, it's not just privileged high-school students: we all tend to view ourselves as above average.

Such inflated self-judgments have been found in study after study, and it's often exactly when we're least competent at a given task that we rate our performance most generously. In a 2006 study published in the journal Medical Education, for example, medical students who scored the lowest on an essay test were the most charitable in their self-evaluations, while high-scoring students judged themselves much more strictly. Poor students, the authors note, "lack insight" into their own inadequacy. Why should this be? Another study, led by Cornell University psychologist David Dunning, offers an enlightening explanation. People who are incompetent, he writes with coauthor Justin Kruger, suffer from a "dual burden": they're not good at what they do, and their very incapability prevents them from recognizing how bad they are.

In Dunning and Kruger's study, subjects scoring at the bottom of the heap on tests of logic, grammar and humor "extremely overestimated" their talents. What these individuals lacked (in addition to clear logic, proper grammar and a sense of humor) was "metacognitive skill": the capacity to monitor how well they're performing. In the absence of that capacity, the subjects arrived at an overly hopeful view of their own abilities. There's a paradox here, the authors note: "The skills that lead to competence in a particular domain are often the very same skills necessary to evaluate competence in that domain." In other words, to get better at judging how well we're doing at an activity, we have to get better at the activity itself.

There are a couple of ways out of this double bind. First, we can learn to make honest comparisons with others. Train yourself to recognize excellence, even when you yourself don't possess it, and compare what you can do against what truly excellent individuals are able to accomplish. Second, seek out feedback that is frequent, accurate and specific. Find a critic who will tell you not only how poorly you're doing, but just what it is that you're doing wrong. As Dunning and Kruger note, success indicates to us that everything went right, but failure is more ambiguous: any number of things could have gone wrong. Use this external feedback to figure out exactly where and when you screwed up.

If we adopt these strategies — and most importantly, teach them to our children — they won't need parents, or a commencement (毕业典礼) speaker, to tell them that they're special. They'll already know that they are, or have a plan to get that way.