When we can see well, we do not think about our eyes very often. It is only when we cannot see perfectly that we come to see how important our eyes are.

    People who are nearsighted can only see things that are very close to their eyes. Many people who do a lot of close work, such as writing, reading and sewing（缝纫）, become nearsighted. Then they have to wear glasses in order to see distant things clearly.

    People who are farsighted（远视的）suffer from just the opposite problem. They can see things that are far away, but they have difficulty reading a book unless they hold it at arm's length. If they want to do much reading, they must get glasses too.

    Other people do not see clearly because their eyes are not exactly the right shape. This, too, can be corrected by glasses. Some people's eyes become cloudy because of cataracts（白内障）. Long ago these people often became blind. Now, however, it is possible to operate on the cataracts and remove them.

    When night falls, colors become fainter to the eye and finally disappear. After your eyes have grown used to the dark, you can see better if you use the sides of your eyes rather than the centers. Sometimes, after dark, you see a small thing to one side of you, which seems to disappear if you turn you head in its direction. This is because when you turn your head, you are looking at the thing too directly. Men on guard duty sometimes think they see something moving to one side of them. When they turn to look straight at it, they cannot see it any more, and they believe they were mistaken. However, this mistake happens because the center of the eye, which is very sensitive(敏感的) in daylight, is not as sensitive as the sides of the eyes after dark.

    If you can speak English，you know a lot of English words. You can read，speak and understand. But there is another kind of language you need to know——the language of the body，a part of what is called non-verbal communication. All over the world，people “talk” with their eyes. When Japanese people meet，they put their hands together. What do American and British do?

    Americans are more informal than the British. They like to be friendly. They use first name，they ask questions and they talk easily about themselves. When they sit down，they like to relax in their chairs and make themselves comfortable.

    British people are more quiet. They take more time to make friends. They like to know you before they ask you home.

    When British and American people meet someone for the first time，they shake hands. They do not usually shake hands with people they know well. Women sometimes kiss their women friends，and men kiss women friends （on one cheek only）.When a man meets a man friend，he just smiles，and says “Hello”. Men do not kiss each other. Even fathers and sons do not often kiss each other.

    After spending a year in Brazil on a student exchange program, her mother recalled(回忆), Marie Colvin returned home to find that her classmates had narrowed down their college choices. “Everyone else was already admitted to college,” her mother, Rosemarie Colvin, said from the family home. “So she took our car and drove up to Yale and said, 'You have to let me in .' ”

    “Impressed--she was a National Merit (全国英才) finalist who had picked up Portuguese in Brazil. Yale did, admitting her to the class of 1978, where she started writing for the Yale Daily News and decided to be a journalist,” her mother said.

    On Wednesday, Marie Colvin, 56, an experienced journalist for The Sunday Times of London, was killed as Syrian forces shelled(炮击) the city of Homs. She was working in a temporary media center that was destroyed in the attack.

    “She was supposed to leave Syria on Wednesday”, Mrs. Colvin said. “Her editor told me he called her yesterday and said it was getting too dangerous and they wanted to take her out. She said she was doing a story and she wanted to finish it.”

    Mrs. Colvin said it was pointless to try to prevent her daughter from going to conflict （冲突）zones. “If you knew my daughter,” she said, “it would have been such a waste of words. She was determined, she was enthusiastic about what she did, it was her life. There was no saying 'Don't do this.' This is who she was, absolutely who she was and what she believed in: cover the story, not just have pictures of it, but bring it to life in the deepest way you could.” “So it was not a surprise when she took an interest in journalism,” her mother said.

    For many, music is as important to the human experience as eating and breathing. We hear music everywhere—at home, the gym, parties and stores. But what kind of music do we prefer to listen to, and when and why do our musical preferences change?

    The relationship between the change of seasons and musical preferences was the focus of a study led by psychologist Terry Pettijohn. He and his team based their research on a previous study that examined the relationship between popular music preferences and the Environmental Security Hypothesis(假设). The results showed that over time, when social and financial conditions were more risky, the songs of the year that were slower, longer, more comforting and serious were most popular. And during periods in which social and financial conditions were generally stable, the result was opposite.

    Building on these findings, Pettijohn and his team wondered if the Hypothesis could also be applied to the change of seasons. For college students, the participants in this study, autumn begins at the start of the school year. Gone are the carefree days of summer, when school is out. Winter means colder temperatures, shorter days, and, in many places in the country, snow. Spring, however, is a different story. It represents a fresh start and when clocks spring forward, we gain an extra hour of daylight. As students walk into summer, they're absorbed in the sunshine and social activities—and enjoy a break from school.

    But do changing seasonal conditions influence musical preferences? To answer this question, the researchers designed two studies. What did they find? Both groups of college students favored more serious music during the seasons of fall and winter, and more active and energetic music during the spring and summer seasons. And these findings, Pettijohn argues, have practical significances.

    Nations in the UN have agreed that the world needs to completely stop plastic waste from entering the oceans. The UN resolution(决议) has no timetable. But ministers at an environment summit believe it will set the course for much tougher policies and send a clear signal to business.

    Under the resolution, governments would establish an international task force(特遣小组) to advise on fighting what the UN's oceans chief has described as a world crisis. One controversial issue is the wish to include businesses on the global task force. Ministers say the problem will not be solved without business, but green groups point out that some firms in the plastics industry have been against restrictions for decades. Vidar Helgesen, a leading voice in the talks, told BBC News, “Business is listening to markets and seeing how marine litter(海洋垃圾) is a growing popular concern. It's possibly the fastest－growing environmental problem and it's therefore a fast－growing problem for business. We need to bring on board those companies that want to change things, and then look at taxes and regulations to make more companies act.”

    Certainly, there has been resistance from plastics firms to the bans. One UN delegate, who did not want to be named, stated that journalists in some countries were being paid by the plastics industry to write stories about job losses following the plastic bag ban. But they did not mention the jobs being created in alternatives, such as labour－intensive basketwork, which provides work for the rural poor. But some governments are standing firm, and the meeting has witnessed individual nations declaring tougher action against single－use plastic bags.

    The UN's spokesman Sam Barratt told BBC News, “Of course we would have liked to have gone further, but this meeting's made real progress. There's now a sense of urgency and energy behind the issue that we haven't quite seen before. What is obvious, though, is that the UN can't solve this problem on its own. We need to do it in partnership with governments, businesses and even individuals.”

Christmas in the United States is traditionally a time of gift-giving and family gatherings. But small towns across the country have their own traditions.

Middleburg, a small town in the state of Virginia, is known for its horses. For more than 50 years, Middleburg has organized a yearly Christmas parade. Men and women ride horses through the woods and fields. They follow hunting dogs as they search for a wild fox. But first, these hunters ride in the yearly parade, wearing their bright red hunting clothes and hats.

John Hale, a citizen of Middleburg says many city people visit his town." We have a lot of people from an urban area that come to visit, but it incorporates a lot of the old traditions." The night-time hayride is one such tradition. Small groups gather under the moonlight on an open wagon (四轮马车) filled with hay (干草). The passengers sing as farm horses pull the wagon slowly across the fields.

There are some newer traditions, too. Trey Matheu works at the nearby Salamander Resort. He says a visit to Middleburg is a chance to slow down for a day. He says Middleburg can be a calming, peaceful place without tension.

"Middleburg is an opportunity to take a step back, to take a deep breath, and understand that even though life is moving on at a very fast pace, there's really an opportunity where you're allowed to step off for a little bit."

Parade organizers say more than 13, 000 people attend even in below freezing weather. But if you ask, you will hear many different reasons why people come to watch the parade:

"I come here because I'm from a small town. I like how everybody comes together."

"I live right down that street, right there. And that's my dog."

Middleburg looks its best at Christmastime. That may be why so many people return each year.