Bad news sells. If it bleeds, it leads. No news is good news, and good news is no news. Those are the classic rules for the evening broadcasts and the morning papers. But now that information is being spread and monitored(监控) in different ways, researchers are discovering new rules. By tracking people's e-mails and online posts, scientists have found that good news can spread faster and farther than disasters and sob stories.

    “The 'if it bleeds' rule works for mass media,” says Jonah Berger, a scholar at the University of Pennsylvania. “They want your eyeballs and don't care how you're feeling. But when you share a story with your friends, you care a lot more how they react. You don't want them to think of you as a Debbie Downer.”

    Researchers analyzing word-of-mouth communication—e-mails, Web posts and reviews, face-to-face conversations—found that it tended to be more positive than negative(消极的), but that didn't necessarily mean people preferred positive news. Was positive news shared more often simply because people experienced more good things than bad things? To test for that possibility, Dr. Berger looked at how people spread a particular set of news stories: thousands of articles on The New York Times' website. He and a colleague analyzed the “most e-mailed” list for six months. One of his first findings was that articles in the science section were much more likely to make the list than non-science articles. He found that science amazed Times' readers and made them want to share this positive feeling with others.

    Readers also tended to share articles that were exciting or funny, or that inspired negative feelings like anger or anxiety, but not articles that left them merely sad. They needed to be aroused(激发) one way or the other, and they preferred good news to bad. The more positive an article, the more likely it was to be shared, as Dr. Berger explains in his new book, “Contagious: Why Things Catch On.”

根据短文内容，选择最佳答案，并将选定答案的字母标号填在题前括号内。

    Customers who come into the Waffle House recognize server Evoni Williams, a soft-spoken 18-year-old from Texas City. It all started with a Facebook post. On the morning of March 3, Laura Wolf was eating breakfast at the Waffle House in La Marque when she overheard an older man, who reminded her of her late father, tell Williams he had trouble with his hands. The man, later identified as regular customer Adrien Charpentier, had an oxygen tank nearby and needed help cutting up his food. “Without hesitation,” Wolf wrote, Williams “took his plate and began cutting up his ham.”

    Impressed, Wolf posted the moment on her Facebook page to share the warmth and kindness with all. The following day, Williams's Facebook notification（关注）began to light up. Her friends saw Wolf's post and tracked her in it.

    Williams had no idea that someone took a photo that morning. The diner was so busy that a line extended outside the door. She said helping Charpentier was reflexive. She has been working at Waffle House since last June to save for college, and this, she figured, was just the right thing to do. “I would want someone to help my grandmother or grandfather,” Williams said.

    The post began to make its rounds in La Marque and eventually landed in front of the city's mayor, Bobby Hocking. He decided to declare March 8 as Williams's day, and also received an email from Texas Southern University President Austin A.Lane, asking if the school could present Williams with a scholarship.

    Williams still works at Waffle House five days a week and plans to do so until she starts classes in the fall at Houston-based Texas Southern. Wolf said Williams does not have a car to get to classes, but some people have offered to start a GoFundMe page for her, proving that a moment of a kindness can change a life.

    In 1977, a dead author of detective stories saved the life of a 19-month-old baby in a most unusual way. The author was Agatha Christie, one of the most successful writers of detective stories in the world.

    In June 1977, a baby girl became seriously ill in Qatar, near Saudi Arabia. Doctors were unable to find out the cause of her illness with confidence, so she was sent to Hammersmith Hospital in London. She was then only semi-conscious and on the "Dangerously Ill" list. A team of doctors hurried to examine the baby only to discover that they, too, were confused by the very unusual symptoms (症状). While they were discussing the baby's case, a nurse asked to speak to them.

    "Excuse me," said Nurse Marsha Maitlan, "but I think the baby is suffering from thallium (铊) poisoning(中毒)."

    "What makes you think that?" Dr. Brown asked. "Thallium poisoning is extremely rare."

    "A few days ago, I was reading a novel called A Pale Horse by Agatha Christie," Nurse Maitlan explained. "In the book, somebody uses thallium poison, and all the symptoms are described. They're exactly the same as the baby's."

    "You're very thoughtful and you may be right," another doctor said. "We'll carry out some tests and find out whether it's thallium or not."

    Tests showed that the baby had indeed been poisoned by thallium, a rare metallic substance(物质) used in making special glass. Once they knew the cause of the illness, the doctors were able to give the baby the correct treatment. She soon recovered and was sent back to Qatar. Later it was reported that the poison might have come from an insecticide (杀虫剂) used in Qatar.

    People from East Asia tend to have more difficulty than those from Europe in distinguishing facial expressions — and a new report published online in Current Biology explains why.

    Rachael Jack from University of Glasgow, said that rather than scanning evenly across a face as Westerners do, Easterners fix their attention on the eyes.

    "We show that Easterners and Westerners look at different face features to read facial expressions," Jack said. "Westerners look at the eyes and the mouth in equal measure, while Easterners favor the eyes and ignore the mouth."

    According to Jack and his colleagues, the discovery shows that communication of human emotions is more complex than previously believed. As a result, facial expressions that had been considered universally recognizable cannot be used reliably to convey emotions in cross­cultural situations.

    The researchers studied cultural differences in the recognition of facial expressions by recording the facial movements of 13 Western people and 13 Eastern people while they observed pictures of expressive faces and put them into categories: happy, sad, surprised, fearful, disgusted, or angry. They compared how accurately participants read those facial expressions using their particular eye movement strategies.

    It turned out that Easterners focused much greater attention on the eyes and made significantly more errors than Westerners did. "The cultural difference in eye movements that they show is probably a reflection of cultural difference in facial expressions," Jack said. "Our data suggests that while Westerners use the whole face to convey emotions, Easterners use the eyes more and the mouth less."

    In short, the data shows that facial expressions are not universal signals of human emotions. From here on, examining how cultural factors have diversified these basic social skills will help our understanding of human emotions. Otherwise, when it comes to communicating emotions across cultures, Easterners and Westerners will find themselves lost in translation.

    Growing up, I was an extremely reserved(腼腆的) boy. I didn't have many friends in primary and middle school and rarely opened up to anyone. I didn't even ask my teacher questions in class. I was scared of the world and the people around.

    As a child, I was scared to do anything without my parents mainly because I was afraid that I would do it badly. I was getting good grades and was well-behaved, but I wasn't happy. It was my belief that I was, for some reason, unable to do the things the others kids could do. I felt inadequate.

    While in my second semester of college, I ran into some information on the Internet about something called social anxiety. I didn't really know much of the disorder. Thus I began to read about some of the symptoms and realized that social anxiety was the thing that hurt me so much.

    It is common knowledge that people with social anxiety experience nervousness in social situations. What a lot of people don't know is that one of the main causes of social anxiety is negative thinking. People having a negative idea of themselves often think that they are ugly or stupid.

    I realized what I was truly afraid of: not being good enough. I was afraid that people would look at me and would not like what they saw; I was scared of rejection. To help deal with these problems, I began to practice meditation(沉思) and other mindfulness exercises. My mind slowly began to change.

    I realized that everyone, from star athletes to noble prize winners, experiences fear in their lives. Whether people are afraid of heights, planes, spiders, or talking to girls, we all experience anxiety and fear. There is no reason for anyone to feel excluded(排除在外的) because something scares them. People with anxiety disorders might have "problems", but there is nothing wrong with them as people. They are just as humans as everyone else.

    If you're DIY-minded, you can build your own solar power system. In some cases, you can even build your own solar panels (电池板), although the amount that you can effectively DIY home solar depends on how much you want to power. Making your own solar panel is a time-consuming process and requires some electrical skills. However, it can also be very rewarding-learning to build your own panel is a great way to understand how solarelectricity is generated.

    Before you can build your own solar panels, you first need to understand how solar cells generate electricity. Once you've bought individual solar cells (they can be purchased online), the basic process for building your own solar panel goes like this: Prepare the backing for your panel. Many DIY solar panel builders prefer to use a wooden board as the base for their solar cell. You'll need to drill holes in the board so that the wires for each cell can pass through. Wire your solar cells together. This requires some experience with electrical work. Use a soldering iron (烙铁) to attach wire to the solar cells and then link each of the cells together. Attach cells to your backing. If possible, attach each solar cell to the backing individually. This makes it easier to replace a single cell in the event that becomes damaged or is not operating properly.

    At this point you have a functional solar panel that can produce electricity when the sun shines. However, a solar panel by itself is not useful. If you are trying to generate electricity to power devices in your home, you need to pair your panel with an inverter (换流器) that will turn direct current (DC) power from the sun into the alternating current (AC) power used in most modern electronic devices.