Since 1984,Philadelphia has been cleaning up its act.One by one,graffiti（涂鸦）covered walls are being changed into outdoor art.So far,more than 1,800 murals（壁画）have been painted.Philadelphia now has more murals than any other American city.

    The walls that were once ugly with graffiti are now covered with beautiful pictures of historical heroes and modern art, thanks to the Mural Arts Program(MAP).Its work makes schools and public places attractive,and its citizens very proud.The program began as part of Philadelphia's Anti-Graffiti Network.Jane Golden is the MAP's artistic director."When people ask me what our program is about,"she says,"I answer them with one word: hope." Each year, the MAP offers youth art programs and workshops.Some onetime graffiti writers even help paint MAP murals.

    The MAP's work,says Golden,is all about developing a sense of community（社区）.When a neighborhood requests a mural,the MAP works with the people there to develop a message.Some messages have been "Safe Streets,"Love and Care," and "Peace Walk".

    The MAP receives up to 50 requests for murals each week. Last year, the workers painted 140 murals."The making of a mural enters people's collective memory as an extraordinary, pleasant moment in neighborhood history," says Golden, who began as a muralist in Los Angeles.

    If you have spent any time living in or visiting a big city in China, you have most likely used the service that Didi provides. The convenient ride-sharing company, now known as Didi Chuxing, was praised last month by Fortune magazine. According to the magazine, it is changing the world with its environmentally friendly solution to getting around in major cities. As the magazine reported: “Didi concluded that last year its car-pooling services helped reduce total car trips in the country by 1 million a day, which saved 500 million liters of gas, cutting 13.5 million tons of carbon emissions (排放) per day.” The transport service was the only Chinese company to make the important magazine's list, and its influence can be felt in many parts of Chinese society.

    Didi is just one example of what is being called the “sharing economy”. The sharing economy is one in which regular people exchange goods and services, usually using an online marketplace. Other similar companies include companies that allow people to rent out their homes to strangers like Airbnb and Couchsurfing, and similar ride sharing services like Uber and Lyft.

    All of these services are possible partly because many people are realizing that they have underused assets in their lives. Millions of people around the world have started renting them out online to earn extra money. They rent their apartments while they are away for the weekend, lend people their cars for money and even sell their spare time.

    The sharing economy is the latest example of the Internet's value to customers. This model is now big enough for regulators and companies to have woken up to it. That is a sign of its great potential. It is time to start caring about sharing.

    Next time a customer comes to your office, offer him a cup of coffee. And when you're doing your holiday shopping online, make sure you're holding a large glass of iced tea. The physical sensation (感觉) of warmth encourages emotional (情感的) warmth, while a cold drink in hand prevents you from making unwise decisions—those are the practical lesson being drawn from recent research by psychologist (心理学家) John A. Bargh.

    Psychologists have known that one person's perception (感知) of another's “warmth” is a powerful determiner in social relationships. Judging someone to be either “warm” or “cold” is a primary consideration, even trumping evidence that a “cold” person may be more capable (能干的). Much of this is rooted in very early childhood experiences, Bargh argues, when babies' sense of the world around them is shaped by physical sensations, particularly warmth and coldness.

    Feelings of “warmth” and “coldness” in social judgments appear to be universal. Although no worldwide study has been done, Bargh says that describing people as “warm” or “cold” is common to many cultures, and studies have found those perceptions influence judgment in dozens of countries.

    To test the relationship between physical and psychological warmth, Bargh conducted an experiment which involved 41 college students. A research assistant who was unaware of the study's hypotheses (假设), handed the students either a hot cup of coffee, or a cold drink, to hold while the researcher filled out a short information form: The drink was then handed back. After that, the students were asked to rate the personality of “Person A” based on a particular description. Those who had briefly held the warm drink regarded Person A as warmer than those who had held the iced drink.

    “We are grounded in our physical experiences even when we think abstractly (抽象的),” says Bargh.

    Everybody hates rats (big mice). But in the earthquake capitals of the world — Japan, Los Angeles, Turkey — rats will soon be man's best friends.

    What happens after an earthquake? We send in rescue dogs. Why? Because they can smell people. Dogs save lives. They help rescuers to find living people. But dogs are big and they can't get into small spaces. So now a new research project is using a smaller animal to save lives: the rat.

    How does it work? First, the rat is trained to smell people. When this happens, the rat's brain gives a signal (信号)．This is sent to a small radio on its back, and then the rescuers follow the radio signals. When the rat's brain activity jumps, the rescuers know that someone is alive. The rat has smelled that person.

    Although there are already robots which can do this job, rats are better. Christian Linster at Cornell University, New York, says, "Robots' noses don't work well when there are other smells around. Rats are good at that." Rats can also see in the dark. They are cheaper and quicker to train than dogs, and unlike robots, they don't need electricity!

    The "rat project" is not finished, but Julie Ryan of International Rescue Organization in Scotland says, "It would be wonderful. A rat could get into spaces we couldn't get to, and a rat would get out if it wasn't safe." Perhaps for the first time in history, people will be happy to see a rat in a building (but only after an earthquake, of course).

    In the home country, a common language gives you the ability to communicate easily with the people around you; and you learn something about your country's history, people's habits, likes and dislikes, customs and traditions. This understanding influences your own behavior, and what you expect of others.

    Living abroad, it doesn't take long to realize that many things don't "work" the same, especially when moving from "the West" to "the East". Besides a different language, each country has its own social system and laws and ways of solving problems. You will find some of them strange and alien. Sometimes you may feel uncomfortable because you realize that things are not the same as you think they are supposed to be. This is what has become known as "Culture Shock".

    Living in an environment with an unfamiliar(不熟悉的)culture can cause stress, anxiety or worse- mental or physical illness in some cases. Culture shock is the shock of experiencing an unknown or new culture. Cross-culture Adjustment is the period of anxiety, great pain and confusion suffered when entering a new culture. It can have effects on a person's emotions and behavior. You should learn to accept and try to be used to different situations. One thing is certain: it is far easier to accept the new order of things than to try to change it.

    Most Asian people can bear foreigners and accept their strange habits and behavior, not only because it might be to their benefit but out of natural politeness and restraint(克制)in front of others. Westerners should not make use of this. They must try to accept and obey local rules and rules of behavior.

Once a blind man fell flat on his face, which was awful but finally harmless. His service dog, however, was trained lo tum to an adult if the owner had an epileptic seizure (癫瘤发作). While the dog did what it was taught, the first person it found was merely annoyed but not alarmed. Thankfully, the dog's owner was not in the situation of medical emergency. But the experience inspired him to share this information on social media, "If a service dog without a person approaches you, it means the person is down and in need of help," the owner explained. "Don't get scared, don't get annoyed, and follow the dog! If the first person doesn't cooperate, it moves on.

Referring to the accident, a TV presenter asked a dog trainer, Olivia, some basic questions about service dogs, including how humans should react if an unaccompanied service dog approaches them.

"What they're going to do is sniff and gently push your leg," the trainer explained, specifically noting that service dogs are not usually trained to jump or bark. "If you see a dog in a vest without a person around it, follow it." When asked if one should say something to indicate they're prepared to follow the dog, Olivia said," there's no clear command. Just start walking wherever the dog leads."

Olivia concluded the TV show by adding that those who rely on service dogs could train their companions to move along to someone else, if the first person the dog came upon reacted negatively to its request. Doing so could finally save the owner's life.