Last spring, I was fortunate to be chosen to join in an exchange study program. The moment I arrived in Paris, I was greeted by a nice French couple who would become my host parents. The bit of French I had taken in high school began coming out of my mouth; speaking the language would only become more natural over the course of the term. At the airport, we all got into the couple's car and began the journey to their townhouse. We talked the whole way, getting to know one another.

    Every day afterwards, I would eat breakfast with the two of them, and then we'd all go our separate ways for the day. In the evening, my host mother would make delicious dinners for the three of us. My experience was exciting until I received some shocking news from my program coordinator（协调人）: There had been a death in my host parents' family and they would have to go away for several weeks to deal with all the business that arises from the death. That afternoon, I had to move out of one family's house and into another.

    The coordinator told me I'd have a roommate and asked whether I would mind sharing a bedroom with an English speaker. To avoid speaking my native language, I asked not to be placed with an English-speaking roommate. When I got to my new room, I introduced myself to my new roommate Paolo, a Brazilian（巴西人）, the same age as I, whom I was surprised to find playing one of my favorite CDs on his computer! In just a few hours, we knew we'd be good friends for the rest of the term.

    I left France with many stories, so when people ask me what my favorite part of the trip was, they always hear about my Brazilian friend Paolo and the weekdays in class, weeknights on the town, and weekends exploring France we enjoyed together. I would recommend an exchange program to anyone who wants to experience foreign cultures and gain meaningful friendships.

    Each passenger needs a farecard to enter and go out .Up to two children under age five may travel free with a paying customer .

    Farecard machines are in every station .Bring small bills because there are no change machines in the stations and farecard machines only provide up to $5 in change.

    Get one ticket of unlimited Metrorall rides with a One Day Pass .Buy it from a farecard machine in Metro stations .Use it after 9:30 a,m. until closing on weekdays , and all day on weekends and holidays .

    Hours of service

    Open 5am  Mon-Fri             7a.m  Sat-Sun

    Open midnight Sun-Thur.

    Last train times vary .

Train times Posted in stations

    Metrobus

    When paying with exact charge , the fare is $1.35.When paying with a SmarTripⓇcard , the fare is

    1.25.

    Fares

    Senior citizens 65 and older and disabled customers may ride for half the regular fare .On Metrorail and Metrobus , use a senior/disabled farecard or Smar/Trip Ⓡ card .For more information about buying senior .disabled farecard , SmarTripⓇcards and passes , please visit MetroOpensDoors .com or call 202-637-7000and 202-637-8000.

    Senior citizens and disabled customers can get free guide on how to use proper Metrobus and Metrorall services by calling 202-962-1100.

    Travel tips (提示)

    Avoid riding during weekday rush periods –before 9:30 a.m. and between 4and 6p.m.

    If you lose something on a bus or train or in a station, please call Lost &Found at 202-962-1195,

    The online economy—from search to email to social media—is built in large part on the fact that consumers are willing to give away their data in exchange for products that are free and easy to use. The assumption behind this trade-off is that without giving up all that data, those products either couldn't be so good or would have to come at a cost.

    But a new working paper, released this week by Lesley Chiou of Occidental College and Catherine Tucker of MIT, suggests that the trade-off may not always be necessary. By studying the effects of privacy regulations in the EU, they attempted to measure whether the anonymization(匿名化) of search data hurts the quality of search results.

    Most search engines capture user data, including IP addresses and other data that can identify a user across multiple visits. This data allows them search companies to improve their algorithms(算法) and to personalize results for the user. At least, that's the idea. To determine whether storage of users' personal data improves search results, Chiou and Tucker looked at how search results from Bring and Yahoo differed before and after changes in the European Commission's rules on data retention(数据保存). In 2008 the Commission recommended that search engines reduce the period over which search engines kept user records. In response, Yahoo decided to strengthen its privacy policy by anonymizing user data after 90 days. In 2010 Microsoft changed its policy, and began deleting IP addresses associated with searches on Bring after six months and all data points intended to identify a user across visits after 18 months. In 2011 Yahoo changed its policy again, this time deciding to store personal data longer—for 18 months rather than 90 days—allowing the researchers yet another chance to measure how changes in data storage affected search results.

    The researchers then looked at data from UK residents' web history before and after the changes. To measure search quality, they looked at the number of repeated searches, a signal of dissatisfaction with search results. In all three cases, they found no statistically significant effect on search result quality following changes in data retention policy. In other words, the decision to anonymize the data didn't appear to impair the search experience. “Our results suggest that the costs of privacy may be lower than currently perceived,” the authors write, though they note that previous studies have come to different conclusions.

    Suppose you are a visitor in the land of Mongolia, some friends ask you to eat with them. What kind of manners do they want you to have? They want you to give a loud burp after you finish eating. Burping would show that you like your food. In some countries, if you give a big burp, you are told to say “Excuse me, please”.

    In many places people like to eat together. But in some parts of Polynesia it is bad manners to be seen eating at all. People show their good manners by turning their backs on others while they eat.

    What are manners like in an East African town? The people try not to see you. They are being polite. You may see a friend. He may not see you at all. If you are polite, you will sit down beside him. You will wait until he finishes what he is doing. Then he will talk to you. Manners are different all over the world. But it is good to know that all manners begin in the same way. People need ways to show that they want to be friends.

    I first met Paul Newman in 1968, when George Roy Hill, the director of Butch Cassidy and the Sundance Kid, introduced us in New York City. When the studio didn't want me for the film - it wanted somebody as well known as Paul — he stood up for me. I don't know how many people would have done that; they would have listened to their agents or the studio powers.

    The friendship that grew out of the experience of making that film and The Sting four years later had its root in the fact that although there was an age difference, we both came from a tradition of theater and live TV. We were respectful of craft(技艺) and focused on digging into the characters we were going to play. Both of us had the qualities and virtues that are typical of American actors: humorous, aggressive, and making fun of each other — but always with an underlying affection. Those were also at the core(核心) of our relationship off the screen.

    We shared the brief that if you're fortunate enough to have success, you should put something back — he with his Newman's Own food and his Hole in the Wall camps for kids who are seriously ill, and me with Sundance and the institute and the festival. Paul and I didn't see each other all that regularly, but sharing that brought us together. We supported each other financially and by showing up at events.

    I last saw him a few months ago. He'd been in and out of the hospital. He and I both knew what the deal was, and we didn't talk about it. Ours was a relationship that didn't need a lot of words.

    With the New Year weeks approaching, you're looking forward to watching the splendid fireworks shows that will welcome 2019 worldwide. Unfortunately, visually impaired and blind people can't experience this joyful celebration. That may change soon thanks to Feeling Fireworks, a fireworks experience invented by the Disney Research Lab in Switzerland.

    To experience the show, users stand before a large flexible screen, place their hands at the base of the screen and move them around to feel the fireworks. Alternatively, their hands can be situated in the center of the screen, where the initial explosions happen, and then moved across to explore other fireworks.

    As the fireworks begin to explode, five nozzles (喷嘴) at the back of the screen start to shoot water, creating movement of water imitating the show. One specializes in the "blooming flower effect", another reproduces the "crackle" effect, and the rest take care of rockets and explosions. A computer controls the timing, and Feeling Fireworks allows users to experience fireworks similar to those in the sky.

    Paul Beardsley, who led the research team, says, "We want blind, visually impaired, and sighted people to all try Feeling Fireworks, and to have a shared and enjoyable memory of a fireworks evening." And the screen displaying the vivid images created by water makes it fun for everyone.

    The low-cost technology is still in its early stage, with only a 66 percent success rate. However, the team plans to continue improving the experience and believes the day when everyone will be able to enjoy the thrill of fireworks shows is not far. When ready, Feeling Fireworks will initially be available only at the Disney theme parks, and then hopefully, at fireworks shows worldwide.