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.”

    That cold January night,I was growing sick of my life in San Francisco.There I was,walking home at one in the morning after a tiring practice at the theatre.With the opening night only a week away,I was still learning my lines.I was having trouble dealing with my part-time job at the bank and my acting at night at the same time.As I walked,I thought seriously about giving up both acting and San Francisco.City life had become too much for me.

    As I walked down empty streets under tall buildings,I felt very small and cold.I began running,both to keep warm and to keep away from any possible robbers.Very few people were still out except a few sad-looking homeless people under blankets.

    About a block from my apartment,I heard a sound behind me.I turned quickly,half expecting to see someone with a knife or a gun.The street was empty.All I saw was a shining streetlight.Still,the noise had made me nervous,so I started to run faster.Not until I reached my apartment building and unlocked the door did I realize what the noise had been.It had been my wallet falling to the sidewalk.

    Suddenly I wasn't cold or tired anymore.I ran out of the door and back to where I'd heard the noise.Although I searched the sidewalk anxiously for fifteen minutes,my wallet was nowhere to be found.

    Just as I was about to give up the search,I heard the garbage truck pull up to the sidewalk next to me.When a voice called from the inside,"Alisa Camacho"I thought I was dreaming.How could this man know my name?The door opened,and out jumped a small red-haired man with an amused look in his eye."Is this what you're looking for" he asked,holding up a small square shape.

    It was nearly 3 a.m. by the time I got into bed.I wouldn't get much sleep that night,but I had gotten my wallet back.I also had gotten back some enjoyment of city life.I realized that the city couldn't be a bad place as long as people were willing to help each other.

    There are two types of people in the world. Although they have equal degree of health and wealth and other comforts of life, one becomes happy, the other becomes unhappy. This arises from the different ways in which they consider things, persons, events and the resulting effects upon their minds.

    People who are to be happy fix their attention on the convenience of things. The pleasant parts of conversation, the well prepared dishes, the goodness of the wine, the fine weather. They enjoy all the cheerful things. Those who are to be unhappy think and speak only of the opposite things. Therefore, they are continually dissatisfied. By their remarks, they sour the pleasure of society, offend (hurt) many people, and make themselves disagreeable everywhere. If this turn of mind was founded in nature, such unhappy persons would be the more to be pitied. The intention of criticizing and being disliked is perhaps taken up by imitation. It grows into a habit, unknown to its possessors. The habit may be strong, but it may be cured when those who have it realize its bad effects on their interests and tastes. I hope this little warning may be of service to them, and help them change this habit.

    Although in fact it is chiefly an act of the imagination, it has serious results in life since it brings on deep sorrow and bad luck. Those people offend many others; nobody loves them, and no one treats them with more than the most common politeness and respect. This frequently puts them in bad temper and draws them into arguments. If they want to get some advantages in social position or fortune(财), nobody wishes them success. Nor will anyone start a step or speak a word to favor their hopes. If they bring on themselves public objections（反对）, no one will defend or excuse them, and many will join to criticize their wrong doings. These should change this bad habit and be pleased with what is pleasing, without worrying needlessly about themselves and others. If they do not, it will be good for others to avoid any contact(接触) with them. Otherwise, it can be unpleasing and sometimes very inconvenient, especially when one becomes mixed up in their quarrels.

    The FBI is investigating the disappearance of a visiting Chinese scholar from a central Illinois university town as a kidnapping(绑架) as her whereabouts(下落) have remained unknown since Friday.

    Zhang Yingying, 26, was last seen on June 9 near the north end of the campus of the University of Illinois at Urbana-Champaign (UIUC), wearing a charcoal-colored baseball cap, a pink and white top, jeans and white tennis shoes and carrying a black backpack. She boarded a Champaign-Urbana Mass Transit District bus and exited the West Springfield and North Mathews avenues at 1:52 pm local time (1852 GMT), police said.

    The FBI has labeled the case as a kidnapping but isn't ruling out anything, said Campus police spokesman Patrick Wade. The suspect appears to be a white male who was in a car and stopped to talk to Zhang on Friday afternoon, the FBI said. Almost one month into a year long appointment at the UIUC campus, Zhang's friends told police that she was heading to an apartment complex in Urbana to sign a lease(租约).

    Security camera footage(连续镜头) on Monday released by university police showed that Zhang talked to the driver of a black Saturn Astra, about five blocks from where she got off a bus in Urbana on Friday afternoon. She entered the car shortly thereafter. Zhang has not been seen or heard from since then and attempts to contact her by phone remain unsuccessful. Authorities have asked the public to help identify that vehicle.

    A massive search has been launched in Urbana in the US state of Illinois since Zhang's disappearance. Police are interviewing with her colleagues, checking local hospitals and coordinating with ride hailing(打车) companies as part of their investigative efforts.

    In an interview with Xinhua through Wechat on Thursday, Zhang Ronggao, father of the ,missing visiting scholar from china's Fujian Province, expressed gratitude to all the people involved in the search and asked US police to accelerate the search.

    Cheating is nothing new. But it's becoming a lot more sophisticated. Republican vice-presidential candidate Sarah Palin was caught out once. A photo taken after the speech she'd given on a "return to conservative principles" showed her left hand covered with crib notes. These included the words "energy, budget cuts, tax" and "lift Americans' spirits". The word "budget" had been crossed out. Video footage also showed her reading from her hand when asked what top three things a conservative-led congress should do. Writing notes on your hand is one way to cheat in an exam. But these days, it's a lot easier ... especially with the Internet.

    Anyone who wants to cheat in an exam can probably find the answers online. There are hundreds of sites offering solutions to all sorts of tests. And it's a lucrative business. One operator in Oregon made $700,000 in about nine months before his arrest. The owner of a website in Ohio pocketed more than $300,000. And a famous overseas site is estimated to sell about 146,000 sets of answers and take in about $10 million per year. Actually, getting hold of the exam answers isn't that hard. Some do the exam themselves and use button cameras or document-scanning pens to copy the tests. Others organize for a group to take tests repeatedly until they can memorize the entire exam between them. Others simply bribe exam administrators.

    At the moment, such business is booming. More and more companies now require their employees to take professional exams. And hundreds of businesses and trade organizations have introduced formal certification programs to measure employee skills. In the US alone, at least 2 million exams are taken every year for information technology certification. But employees also have to take exams for all sorts of professions from crane operators to court reporters to school bus drivers and financial planners. Test officials estimate that hundreds of thousands of test-takers have used the Internet to buy answers for professional tests. And a recent survey found that 28 percent of test centres had at least one cheating incident over the last five years. In one incident, tens of thousands of soldiers obtained answers to tests in a range of military skills.

    Many see this as a cause for concern. Many tests are for work in sensitive areas such as defence installations and hospitals. Now, how would you feel if you knew that the people in charge of the computers controlling nuclear weapons might have cheated in their tests, and may not really know what they're doing?

Freshmen at Central Valley High in Ceres had a busy week of good deeds, tied to Pay It Forward Day, April 30, and an urge to show the world that teens can be awesome.

Kids in Success 101 spent first period making sandwiches for the homeless. The classes, taught by Natalie Rowell and Becky Lynch, got to hand 200 bagged sandwiches to the charity giving out the food. "They got to really see what an impact they had. It was inspiring and heartwarming," Rowell said. Besides, students also made blankets to send to soldiers, and created 45 flower arrangements for senior people at the Hale Aloha Home in Ceres. "They were nervous going into it. But when they saw how happy the elderly were, the reality of what they did really surfaced," Rowell said.

Rowell said she liked working with children. get to see how they learn. "It's different from how we learn, but we're kind of the same because they struggle in some of the subjects that we find hard as well."

Success 101 was tailor-made for students with that kind of insight. The first-period class includes study help, speakers on teen subjects and an overall focus on looking past high school, figuring out the steps to create their future. "Some kids need that little push. In this class, that's what we do, we give them that little push," Lynch added. "Success would be beneficial for all ninth-grade students. Since the start of the year, I really see a change in them."

Raquel Alfaro, a teen participant who worked with the younger kids, likes the Pay It Forward idea. "This helps us show adults, and also kids, that we're doing something different and that we're not as mean and selfish as they think we are," Alfaro said.