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.”

    The mobile phone has become a problem for high schools. Some high-school students in Australia are not allowed to carry mobile phones during school hours.

    The mobile phone used among children has become a problem for the school years. Several children have got mobile phones as Christmas presents, and more students want them. Marry Brown, a headmaster, said that the mobile phone was a distraction to students during school hours and it also gave teachers so much trouble in their classrooms. Teachers also say that sometimes students might use phone messages to cheat during exams.

    She said some schools had tried to ban mobile phones.  Some parents felt unhappy because they couldn't get in touch with their children.

    Many teachers said students should not have mobile phones at school, if there was a good reason, they could leave their phones at school office. They also said phones were easily lost and were a distraction for studies.

    Many people say that they understand why parents would want their children to have phones, but they think schools should let students know when they can use their mobile phones.

When I was in my third year at university, my roommates were American footballers, so I decided to join them. I remember seeing them in front of me wearing pads (防护垫), and thinking they were going to kill me. I got tackled (阻截) so hard that I was frightened. But then I realized it was just physical contact. I've been addicted since.

The fundamental aim of the game is to score by running with the ball into, or receiving the ball inside the opposition's end zone. Every player on the field has a set responsibility. I'm a running back. My job is using my speed, strength and skill to carry the ball and keep running until either I score or I get put down. And it does hurt.

I've broken two fingers and hurt my shoulder, but the worst was when I trapped the ligaments (韧带) in the back of my leg. I had to take a year out. But none of that put me off- all I could think was how I was going to come back stronger. Besides training with the team, I now have my gym routine to get fitter, faster and stronger.

Although people think American football is aggressive, there's much more to it. Every team has its own playbook, outlining everyone's role in different scenes. My playbook was 73 pages long. Words can't describe how it feels when it all comes together on the field.

American football has changed my life for the better. I've learned time management, how to take responsibility for my action, and how much I treasure being part of a team. Within the four lines of the field, it is physical. Emotions run high. If you're on the opposing team, you are my enemy. But once the game is done, we're like a big family.

How Women Were Freed From Their Homes

    As late as 1800, a woman's only place was in her home. Women in business were unheard of. No respectable woman would dream of entering what was strictly a “man's world”. Even if she would, what could she do? Men were sure that no woman could do a job well outside her home.  This was a widely-accepted idea. When the famous Bronte sisters began writing books in 1846, they had to resort to using men's names as aliases.

    Teaching was the first profession opened to women, soon after 1800. But even that was not easy for women to take because most high schools and colleges were open only to men. Oberlin College in Ohio was the first college in America to take in women.

    Nursing was regarded as a respectable profession for women only after Florence Nightingale won high credit for her nursing career and became famous. Miss Nightingale opened the first training school for nursing in 1860 in England.

    The invention of typewriters in 1867 helped to bring women out of their homes to join the business world. Because women are careful and have nimble fingers, businessmen found that they were well suited to this kind of work.

    By 1890, tens of thousands of women were working in schools, hospitals, shops, offices, and factories both in England and the States. Some even managed to become doctors or lawyers. The idea of women working in business and other circles was accepted. 

    NASA might be famous for sending rockets up to space quickly. But it will be more famous for making your next holiday come more quickly.

    The space agency is working on a new plane, which could solve the problems of supersonic(超音速的) flight and vastly increase the speed of journeys abroad. If successful, the plane would be able to fly between New York and London in just three hours. And it would reduce the time spent flying other journeys by a half, since it could be used more broadly. Until now, the problem with such planes has been the sonic boom(声爆), made famous by the original Concorde. That happens when a plane reaches supersonic speeds.

    It is a thunderous noise that upsets people on the ground— disturbing animals and even causing physical problems to materials and houses underneath. It was that effect that led Congress to ban such planes from being used over the US land, a decision that in turn was responsible for Concorde's failing to be commercially used.

    In view of the problem, the space agency has developed a new technology and tried it out in wind tunnels, and now believes that it could be put to commercial use. That plane will fly as high as 55,000 feet—far higher than normal planes—and make a sound of only 60 decibels. That's far less than 90 decibels thrown out by normal planes, and is roughly in line with a car on the motorway or a busy restaurant.

    “As long as we can get endorsement from the general public, the plane will probably be something that's acceptable,” said Peter Coen, project manager for NASA's commercial supersonic research team, in a new Bloomberg report. “If we get approved, we will have the full-sized version of the plane tried out and the plane will be put into use.”

    WHERE TO STAY

    With its modern art museums, hidden basement bars and fast-developing food scene, Buenos Aires, Argentina's capital, is one of the most attractive cities in Latin America. Contact us, and we offer you some special hotels.

    Querido

    This is a cheerful seven-room townhouse in Villa Crespo. Its rooms are big, and each is specially designed. A hearty breakfast is served in the dining room. Querido's convenient location means Palermo Soho is a short walk away.

Doubles from ￡73, querido.com

    Home Hotel

    Design and comfort are key at this 20-room hotel in Palermo Hollywood. From Florence Knoll furniture to William Morris wallpaper, every detail has been hand-picked by the British-argentinian owners. There's an outdoor swimming pool and a garden with green trees. Weekend brunch（早午餐）is a welcome choice for tourists.

    Doubles from ￡90, homehotel.com

    Tango Hotel

    A big makeover（翻新）changed this former sewing machine factory in Monserrat into a 59-room hotel. Despite the busy location, the environment is good.

    Doubles from ＄75, tangohotel.com

    La Querencia

    Close to Constitucion, this comfortable four-room hotel in San Telmo is run by a Frenchman, Yann. Decoration is simple but the place is spotless. Guests can make use of the kitchen where Yann prepares breakfast and enjoy their meals in the dining room or in the yard.

    Doubles from ＄55, laquerencia.com