Mark Twain, the famous American writer and a great master of humor, liked to play jokes on others. But once a joke was played on him. One day Mark Twain was invited to give a talk in a small town. At lunch he met a young man, one of his friends.

    The young man said that he had an uncle with him. He told Mark Twain that his uncle never laughed or smiled, and that nobody and nothing was able to make his uncle smile or laugh.

    "You bring your uncle to my talk this evening," said Mark Twain. "I'm sure I can make him laugh."

    That evening the young man and his uncle sat in the front. Mark Twain began to speak. He told several funny stories and made everyone in the room laugh. But the man never even smiled. Mark Twain told more funny stories, but the old man still kept quiet. Mark Twain continued to tell his funny stories. Finally he stopped. He was tired and quite disappointed.

    Some days later, Mark Twain told another friend what had happened." Oh," said his friend, "I know that man. He's been deaf for years."

    {#blank#}1{#/blank#}We achieve it actively by direct experience, by testing and proving an idea, or by reasoning. We achieve knowledge passively by being told by someone else. Most of the learning that takes place in the classroom and the kind that happens when we watch TV or read newspapers or magazines is passive. Conditioned as we are to passive learning, it's not surprising that we depend on it in our everyday communication with friends and co-workers.{#blank#}2{#/blank#} It makes us tend to accept what we are told even when it is little more than hearsay and rumor.

    Did you ever play the game Rumor? It begins when one person writes down a message but doesn't show it to anyone. Then the person whispers it, word for word, to another person. That person, in turn, whispers it to still another, and so on, through all the people playing the game. The last person writes down the message word for word as he or she hears it. Then the two written statements are compared.{#blank#}3{#/blank#}．

    {#blank#}4{#/blank#} The simple fact that people repeat a story in their own words changes the story. Then, too, most people listen imperfectly. And many enjoy adding their own creative touch to a story, trying to improve on it, stamping it with their own personal style. Yet those who hear it think they know.

    {#blank#}5{#/blank#} A statement of opinion by one writer may be restated as a fact by another, who may in turn be quoted by yet another; and this process may continue, unless it occurs to someone to question the facts on which the original writer based his opinion or to challenge the interpretation he placed upon those facts.

A. Typically, the original message has changed.

B. Finally everybody gets the meaning.

C. Unfortunately, passive learning has a serious problem.

D. Knowledge is passed down from generation to generation.

E. That's what happens in daily life.

F. This process is also found among scholars and authors.

G. We can achieve knowledge either actively or passively.

    There is a story about a man who lost his legs and left arm in an accident. After the accident, only a finger and thumb on his right hand remained.

    He was a brilliant, creative, and educated man. He had gained a lot of experience while traveling around the world, so he became very depressed after his accident. He was afraid that he would spend the rest of his life suffering and would no longer be able to spend his life in a meaningful way. Then, he realized that he still had partial function of his right hand and could still write even though it was very difficult. An idea occurred to him. “Why not write to other people who need encouragement? ”

    He wrote to the prison ministry about sending letters to the prisoners. The prison minister replied, “Writing to the prisoners is acceptable, but your letters will not be answered. ”

    Filled with excitement, the man knew he could write his letters. He began sending one-way messages of God's love, hope, strength, and encouragement. He wrote twice a week, testing his strength and ability to the limit. He poured his heart and soul into his words and shared his experience, sense of humor, optimism, and faith.

    It was difficult to write those letters, especially without hope of a reply. One day he received a letter from the prison ministry. It was a short note from the officer who monitored and checked the prison mail.

    The letter said, “Please write on the best paper you can afford. Your letters are passed from cell to cell until they literally fall to pieces! ”

    No matter what circumstances life may present, we all have unique experiences, abilities, and God-given talents. We can discover ways to reach others who desperately need messages of encouragement and strength.

    On Sept. 15, TripAdvisor, one of the world's largest travel review websites, named the world's top 25 museums in its Travelers' Choice Award according to the reviews and opinions of travelers worldwide. Now let's take a look at the top four museums which are ranked as follows by the popularity around the world.

    Metropolitan Museum of Art, New York City

    It is the largest museum in the Western Hemisphere, with a collection of 2 million items from more than 5,000 years of world culture. The iconic museum includes important collections from ancient Egypt and medieval Europe as well as ancient Greece and Rome. Here, visitors can get lost in different centuries: They can see the Temple of Dendur from early Egypt, Dutch painter Vincent van Gogh's Wheatfield With Cypresses an US pop Andy Warhol's Souper Dress, all in one place.

    Muse d'Orsay, Paris

    Located in the center of Paris on the bank of the River Seine, the Musee d'Orsay houses the world's most amazing collections of impressionist and post-impressionist art. It offers the chance to view major works from greats like Van Gogh and Claude Monet. The museum is famous for being home to Starry Night over the Rhone, an oil painting by Van Gogh that is often praised along with his masterpiece Starry Night.

    Art Institute of Chicago, Illinois

    It was named the world's best museum in 2014. The world-famous Windy City museum houses nearly 300,000 works, including one of the largest collections of modern art, including pieces such as Spanish painter Pablo Picasso's The Old Guitarist, US artist Georgia O'Keeffe's Black Cross and French artist Henri Matisse's Bathers by a River. A TripAdvisor reviewer commented, “No matter how many times I visit, it never gets old. Paintings from every era, works from every great artist.”

    Museo Nacional del Prado, Madrid

    Nowhere is able to present the entire history of Spanish art like the Museo Nacional del Prado.

    Here, visitors can enjoy a detailed view of the Spanish school of the Modem Age. Outstanding masterpieces by artists such as Diego Velazquez, Francisco Goya and Joaquiin Sorolla make up an internationally-famous collection. The Italian school is another highlight of the museum's collection, as it includes the 15^th century masterpieces such as The Annunciation by Fra Angelico, The Death of the Virgin by Andrea Mantegna and The Dead Christ Supported by Angels by Antonello da Messina.

For hundreds of years, Africans have preserved their history through storytelling. But some Africans worry that oral traditions will be lost to the Internet connections and social media.

This has led a Nigerian woman named Elizabeth Kperrun to create a mobile phone application as a way to preserve African folk stories. She calls her mobile app AfroTalez, which tells children's stories that teach moral lessons.

"We can't teach kids something by telling them, 'Don't do this'. I think kids need context to understand. In a story somebody stole something and then something bad happened to them. Alternatively, somebody else did something good and they ended up happy or rich."

"Hello children. My name is Liz and I'd like to tell you a story about tortoises, elephants, and ..." The voice of "Aunt Liz" narrates the story, while a full-screen animation appears. An arrow signals when it's time to move on. There are also quizzes on object recognition and counting throughout.

Kperrun asks her older relatives to help her collect stories for the application. The stories come from an ethnic group living in southeast Nigeria and northwest Cameroon. "I want to keep it centered on folk stories, not the ones that Walt Disney has made really popular... It's fair and respectful to keep certain cultures alive because folk stories are part of the tapestry that keeps cultures together." Kperrun once said.

Kperrun writes and reads the stories. Her business partner and husband Idamiebi Ilamina-Eremie does the animation (动画).

AfroTalez is available for Android users and can be downloaded for free. So far, AfroTalez has more than 50,000 users. Funding for the app has been a major challenge. Kperrun hopes to use a crowdfunding campaign to help fund the next version of AfroTalez to be released soon.

Kperrun believes technology doesn't have to destroy or replace traditions. Her goal is to combine them to keep African culture alive. She says "Africa is our home, but we are so eager to become Western that we are forgetting things that are really important and should be passed on of who we are, and I don't think that's right."

Some people often wonder whether they are fighting a battle with their genes to maintain a healthy weight. In fact, researchers have provided plenty of evidence that people are born with tendencies to be lighter or heavier. For example, studies of identical twins have revealed great similarity in their overall weight. Part of this similarity may be explained by the finding that some people are born to burn a lot of calories just through ordinary day-to-day activities while others are not. Those who are not are more at risk for weight gain.

Researchers have discovered some of the actual genetic mechanisms (机制) that may make some individuals more likely to be obese. For example, a gene has been found that appears to control signals to the brain that enough fat has been stored in the body in the course of a meal—so the individual should stop eating. The gene influences the production of leptin (瘦蛋白), which keeps appetite under control. If leptin doesn't work well, it is likely that individuals will continue to eat. Thus the gene that controls leptin appears to have a critical influence on the potential for obesity.

The confirmation that leptin plays a role in weight control has encouraged researchers to identify and understand other weight-related genes. Recent attention has focused on a gene called GAD2. GAD2 helps control the amount of the neurotransmitter (神经递质) GABA. In general, when more GABA is available, appetite is increased. For that reason, people who have a form of GAD2 that allows more GABA to be available may be at risk for overeating. You can see that GAD2 is not directly an obesity gene. Rather it has an indirect influence on obesity through its direct influence on GABA.

Genetic research holds out the promise of innovative solutions to obesity. Researchers hope that an understanding of the link between genus and weight control will enable them to provide new drug treatments. Nonetheless, even the most optimistic researchers provide a warning: "Innovative drugs will be effective only when they are used along with lifestyle changes."