Sometimes, you just can't help it. Maybe you're watching a sad movie, or thinking about the friend who moved away. Next thing you know, your eyes are watering, and you havetears running down your cheeks. Why do peoplecry when they are emotional? What are tears? Scientists are working hard to find the answers to these questions.

    Ad Vingerhoets is a professor of psychology at Tilburg University, in the Netherlands. He is one ofthe few scientists in the world who have studied crying. According to Vingerhoets, there are three types of tears. Basal tearsare the first type. Theylubricate(润滑) the eyes andact as a protective barrier between the eye and the rest of the World. Next arereflex tears. They wash youreyes clean when something gets in them. Finally, there are emotional tears. “These are released in response to emotional states, ”explains Vingerhoets. “Especially when we feel helpless.”

    Scientists believe that crying has something to do with how humans developed and learned to depend on each other.“Humans are very complex social creatures,”says Lauren Bylsma, a professor at the University of Pittsburgh, in Pennsylvania.“It seems that tears serve to arouse help and support from others," She says. “Another reason we weep is that humans have the longest developmental period of almost any animal. It takes along time to grow up. ”

    Vingerhoets agrees. “I think that the reason why humans shed tears(流眼泪) has somethingto do with our childhood,”he says. “That's the time when we are stir dependent on adults for love and protection and care. The major advantage of emotional tears is that you can target them at a specific person.”Vingerhoets says this ability to target someone could have come in hand in prehistorictimes, when humans were living among dangerous animals. Crying couldattract predators(捕食者). Tears were asafer way to get attention. In this case, it is better to use a silent signal to ask for help,”he says.

    Vingerhoets and Bylsma do frequent studies to better understand why humans cry. According to Byhma, there is still much more to discover. “It's surprising,”she says,“how much we still don't know.”

    My elder cousin Ted liked complaining almost about everything. When he faced a problem, he always chose to complain about it instead of finding a way to solve it. That was not right. Ted was healthy and had received a good education. He should and could find a good job and work hard to feed himself, but he just complained all day, drifting from one job to another. One day, I read about a farmer called Chris and told Ted about the farmer.

    Chris works hard, performs many jobs around the farm. But Chris is not exactly like other farmers. What makes him different is that he was born without arms or legs. But this has not stopped him from working hard and getting things done.

    Now, you may ask, is this possible? Like many other amazing people who have no arms or legs, Chris does not focus on what he can't do, but rather on what he can do. And he can do a lot! He drives farm vehicles and looks after crops. Once you see Chris in action, you will think there is nothing he could not do.

    Chris is a great example of a person who is making the most of his gifts. His positive attitude and courage make him a true inspiration.

    After I told Ted about Chris, he became silent. Compared with Chris, Ted was much luckier. Then luckily, I saw Ted's change.

    Do you like complaining? If you do, think about Chris. Such a man chooses to stay positive. Why don't we?

    Around three forty-five on a rainy Saturday morning, I was woken up by the sound of my pager(呼机) beeping. As a volunteer firefighter and emergency medical technician, I can never count on a full night of sleep. I pulled myself out of bed and went toward the desk to grab my radio. Our crew was being sent to a nearby home where a man was in cardiac arrest (心脏骤停). We found the man lying on the kitchen floor with his wife beside him. We rushed the patient to the hospital, but despite our efforts, we were unable to save his life.

    In my line of life, I rarely get any recognition from the patients we treat, or from their loved ones. But that night, a man's wife approached us, and through her tears, whispered, “Thank you.” Then she hugged each of us. She knew we answered her late-night call for help, even though the ending was not positive.

    There is something deeply rewarding about helping people in these circumstances. Sometimes, I'm able to make their worst day a bit better: like seeing the tears of an injured child turn into a smile when I gave him an interesting toy; or watching a terrified mother's screams turn into tears of joy when she realized her baby was going to be fine.

    Experiences like these allow me to see the impact my work has on others. At the same time, I also know the effect it has had on my own life. As a teenager, I felt awkward when my dad hugged me and said, “ I love you, my dear son.” I was equally uncomfortable and responded, “I love you.” But then I imagined him lying on the kitchen floor that rainy night and realized that my opportunity to say those three words could—at any moment—be taken away forever. Now, I extremely treasure the moment when my father says those three words to me. I've learned to appreciate every relationship I have, to tell people I care about them, and to never take anything in life for granted.

    Allan Guei, 18, was a star basketball player at Compton High School in the Los Angeles area before he graduated last month. His good grades made him eligible for an unusual competition: A free-throw contest in the Compton High gymnasium. The top prize: ＄40,000 in scholarship money.

    Guei, whose parents immigrated to the United States from the Ivory Coast, knew how much that financial aid could mean for his family. He was also feeling a fair share of pressure as students and teachers crushed into the gym to watch Guei and seven other randomly compete against each other.

    Guei won the free-throw contest by one basket and netted the ＄40,000. But it's what he did next that's truly astonishing.

In the weeks following the March free-throw competition, Guei learned that he'd scored a full-ride basketball scholarship to California State University—Northridge. NCAA(全国大学生体育协会)rules allowed Guei to accept the athletic scholarship and also keep most of the ＄40,000 he had won.

    But Guei couldn't stop thinking about the seven talented runners-up from the free-throw contest. They, too, had dreams and very real needs. So, he asked Principal Jesse Jones to make a surprise announcement at Compton High's graduation ceremony: Geui wanted to donate the ＄40,000 to the other seven students.

    “I've already been blessed so much and I know we're living with a bad economy, so I know this money can really help my classmates,” Guei said in a statement. “It was the right decision.”

    Guei elaborated on his decision to give the money away in an interview with ESPN(体育电视网): “I was already well taken care of to go to school, to go to university for free… I felt like they needed it more than I did.”

    We have encountered a crisis around the corner. You mean global warming? The world economy? No, the decline of reading. People are just not doing it anymore, especially the young. Who's responsible?

Actually, it's more like, what is responsible? The Internet, of course, and everything that comes with it – Facebook, Twitter. You can write your own list.

    There's been a warning about the imminent death of literate civilization for a long time. In the 20th century, first it was the movies, then radio, then television that seemed to spell doom for the written world. None did. Reading survived; in fact it not only survived, it has flourished. The world is more literate than ever before – there are more and more readers, and more and more books.

    The fact that we often get our reading material online today is not something we should worry over. The electronic and digital revolution of the last two decades has arguably shown the way forward for reading and for writing. Take the arrival of e-book readers as an example.

    Devices like Kindle make reading more convenient and are a lot more environmentally friendly than the traditional paper book.

    As technology makes new ways of writing possible, new ways of reading are possible. Interconnectivity allows for the possibility of a reading experience that was barely imaginable before. Where traditional books had to make do with photographs and illustrations, an e-book can provide readers with an unlimited number of links: to texts, pictures, and videos. In the future, the way people write novels, history, and philosophy will resemble nothing seen in the past.

    On the other hand, there is the danger of trivialization. One Twitter group is offering its followers single-sentence-long "digests" of the great novels. War and Peace in a sentence? You must be joking. We should fear the fragmentation of reading. There is the danger that the high-speed connectivity of the Internet will reduce our attention span—that we will be incapable of reading anything of length or which requires deep concentration.

    In such a fast-changing world, in which reality seems to be remade each day, we need the ability to focus and understand what is happening to us. This has always been the function of literature and we should be careful not to let it disappear. Our society needs to be able to imagine the possibility of someone utterly in tune with modern technology but able to make sense of a dynamic, confusing world.

    In the 15th century, Johannes Guttenberg's invention of the printing press in Europe had a huge impact on civilization. Once upon a time the physical book was a challenging thing. We should remember this before we assume that technology is out to destroy traditional culture.

    If you want to spark a heated debate at a dinner party, bring up the topic of genetically modified foods. For many people, the concept of genetically altered, high-tech crop production raises all kinds of environmental, healthy, safety and ethical questions. Particularly in countries with long a grain traditions—and vocal green lobbies—the idea seems against nature.

    In fact, genetically modified foods are already very much apart of our lives. A third of corn and more than half the soybeans and cotton grown in the U. S. last year were the product of biotechnology, according to the Department of Agriculture. More than 65 million acres of genetically modified crops will be planted in the U. S. this year. The genetic genie(鬼怪) is out of the bottle.

    Yet there are clearly some very real issues that need to be resolved. Like any new product entering the food chain, genetically modified foods must be subjected to rigorous testing. In wealthy countries, the debate about biotech is tempered by the fact that we have a rich array of foods to choose from and a supply that far exceeds our needs. In developing countries desperate to feed fast-growing and underfed populations, the issue is simpler and much more urgent: Do the benefits of biotech outweigh the risks？

    The statistics on population growth and hunger are disturbing. Last year the world's population reached 6 billion. The U. N. estimates that nearly 800 million people around the world are undernourished. The effects are devastating. About 400 million women of child-bearing age are iron deficient, which means their babies are exposed to various birth defects. As many as 100 million children suffer from vitamin A deficiency, a leading cause of blindness.

    How can biotech help? Biotechnologists have developed genetically modified rice that is fortified with beta-carotene—which the body converts into vitamin A—and additional iron, and they are working on other kinds of nutritionally improved crops. Biotech can also improve farming productivity in places where food shortages are caused by crop damage attributable to pests, drought, poor soil and crop viruses, bacteria or fungi.