When the residents of Buenos Aires want to change the pesos they do not trust into the dollars they do, they go to an office that acts as a front for thriving illegal exchange market.

    As the couriers carry their bundles of pesos around Buenos Aires, they pass grand buildings like the Teatro Colon, an opera house that opened in 1908, and the Retiro railway station, completed in 1915. In the 43 years leading up to 1914, GDP had grown at an annual rate of 6%, the fastest recorded in the world. In 1914 half of Buenos Aires's population was foreign-born. Its income per head was 92% of the average of 16 rich economies.

    It never got better than this. Its income per head is now 43% of those same 16 rich economies; it trails Chile and Uruguay in its own backyard.

    The country's dramatic decline has long puzzled economists. “If a guy has been hit___shots it's hard to work out which one of them killed him.” says Rafael di Tella. But three deep-lying explanations help to throw light on the country's decline. Firstly, Argentina may have been rich 100 years ago but it was not modern. The second theory stresses the role of trade policy. Thirdly, when it needed to change, Argentina lacked the institutions to create successful policies.

    Argentina was rich in 1914 because of commodities; its industrial base was only weakly developed. The landowners who made Argentina rich were not so bothered about educating it: cheap labor was what counted.

    Without a good education system, Argentina struggled to create competitive industries. It had benefited from technology in its Belle Epoque period, but Argentina mainly consumed technology from abroad rather than inventing its own.

    Argentina had become rich by making a triple bet on agriculture, open market and Britain, its biggest trading partner. If that bet turned sour, it would require a severe adjustment. The First World War delivered the initial blow to trade. Next came the Depression, which crushed the open trading system on which Argentina depended. Dependence on Britain, another country in decline, backfired(失败) as Argentina's favored export market signed preferential deals with Commonwealth countries.

    After the Second World War, when the rich world began its slow return to free trade with the negotiation of the General Agreement on Tariffs and Trade in 1947, Argentina had become a more closed economy. An institution to control foreign trade was created in 1946; the share of trade as a percentage of GDP continued to fall. High food prices meant big profits for farmers but empty stomachs for ordinary Argentines. Open borders increased farmers' taking but sharpened competition from abroad for domestic industry. Heavy export taxes on crops allow the state to top up its decreasing foreign-exchange reserves; limits on wheat exports create surpluses(过剩) that drive down local prices. But they also dissuade farmers from planting more land, enabling other countries to steal market shares.

    Earthquakes are something that people fear. There are some places that have few or no earthquakes. Most places in the world, however, have them regularly. Countries that have a lot of earthquakes are usually quite mountainous.

    The most talked about earthquake in the United States was in San Francisco in 1906. Over 700 people died in it. The strongest one in North America was in 1964. It happened in Alaska.

    Strong earthquakes are not always the ones that kill the most people. In 1755, one of the strongest earthquakes ever recorded was felt in Portugal. Around 2,000 people died.

    In 1923, a very strong earthquake hit Tokyo, Yokohama area of Japan. A hundred and forty thousand people died. Most of them died in fires which followed the earthquake.

    One of the worst earthquakes ever was in China in 2008. It killed a large number of people. The worst earthquake ever reported was also in China, in which 400,000 people were killed or injured. This earthquake happened in 1556.

    Earthquakes worry people a lot. The reason is that we often do not know when they are coming. People cannot prepare for earthquakes.

    Most people feel lonely sometimes, but it usually lasts only between a few minutes and a few hours. This kind of loneliness is not serious. In fact, it is quite normal. For some people, though, loneliness can last for years. Now researchers say there are three different types of loneliness.

    The first kind of loneliness is temporary. This is the most common type. It usually disappears quickly and does not require any special attention. The second kind, situational loneliness, is a natural result of a particular situation－for example, the death of a loved one, or moving to a new place. Although this kind of loneliness can cause physical problems, such as headaches and sleeplessness, it usually does not last for more than a year.

    The third kind of loneliness is the most severe. Unlike the second type, chronic(长期的) loneliness usually lasts more than two years and has no specific cause. People who experience habitual loneliness have problem socializing and becoming close to others unfortunately, many chronically lonely people think there is little or nothing they can do to improve their condition.

    Many researchers agree that the loneliest people are between the ages 18 and 25, so a group of psychologists decided to study a group of college students. They found that more than 50% of the students were situationally lonely at the beginning of the term as a result of their new circumstances, but had adjusted after a few months, 13% were still lonely after seven months due to shyness and fear. They felt very uncomfortable meeting strangers, even though they understood that their fear was not reasonable. The situationally lonely students overcame their loneliness by making new friends, but the chronically lonely remained unhappy because they were afraid to do so.

    Psychologists are trying to find ways to help habitually lonely people for two reasons: they are unhappy and unable to socialize and there is a connection between chronic loneliness and serious illness such as heart disease. While temporary and situational loneliness can be a normal, healthy part of life, chronic loneliness can be a very sad, and sometimes dangerous condition.

    Feel nervous on the first day of school? You are not alone! Here is some advice on how to make you feel comfortable.

    Get ready the night before. Plan out what you're going to wear and what you will need for class. Then get a nice, long sleep. There's nothing worse than looking terrible on the first day of school. If you don't want to oversleep, set an alarm on your phone, or alarm clock to wake you up on time.

    Eat a good breakfast. You'd be surprised at how much happier and more focused you'll be after eating a good breakfast. Have a healthy breakfast. A rich breakfast may make you feel lazy and sugar rich foods may affect your ability to stay focused.

    Decide whether to take the bus, walk, or have a ride from your parents. It's your call. If you want something familiar, take a bus ride and sit next to someone you already know. However, if you are really nervous, you can ask your mom or dad to drive you to school, but expect that there will be heavy traffic.

    Smile and be friendly! You want to seem easy to get along with and that you had the best summer. Smile and be friendly. Instead of coming up as a boring person, compliment people. Everyone needs a little confidence and is happy when praised on the first day of school.

No one could have expected that slow-moving Qigong {#blank#}1{#/blank#}(become) popular among Chinese young people in the past several years. Short videos of young Chinese doing traditional fitness Qigong have flooded video websites, among {#blank#}2{#/blank#} a video of Baduanjin has been played for more than 10 million times and received over 6,000 comments on a video sharing platform {#blank#}3{#/blank#}(target) young people.

Baduanjin is one of the oldest fitness methods {#blank#}4{#/blank#}(stay) healthy in China, originally created over 800 years ago during the Song Dynasty. The name refers to how the eight individual movements provide a soft quality {#blank#}5{#/blank#} the movement of the body.

Compared with more {#blank#}6{#/blank#}(physical) demanding sports such as the ball games or swimming, Baduanjin is slow and usually accompanied by restful music, so it used to be considered as the sport meant for the elders. However, not requiring much space, equipment or time, it's perfect for office workers, as they often suffer from back and neck pain {#blank#}7{#/blank#}(cause) by sitting in front of computers for hours.

"I've been doing Baduanjin for a couple of {#blank#}8{#/blank#}(month), which makes me sleep well and get strong,"{#blank#}9{#/blank#} young netizen commented below the video. "I owe big thanks to Baduanjin as it offers a much {#blank#}10{#/blank#}(healthy) lifestyle."

Every year on April 1,April Fools' Day is celebrated in many countries around the world.In France,it's called "Poisson d' Avril"or"Fish of April".In Scotland, the holiday is often called "Gowkie Day".In Iraq, the holiday is called "Kithbet Neesan" or "April Lie".

History experts say people have celebrated April Fools ' Day for a long time.Some believe April Fools' Day comes from the ancient Romans more than two thousand years ago, which was a day of playing games and pretending to be someone else.

Others say the day for fooling began in France in 1564.when King Charles changed the yearly calendar.He moved New Year's Day from April 1 to January I Many people did not know about the change because of communication problems then.Some people continued to celebrate New Year's Day on April 1.Other people called them April Fools and played jokes on them.

In the United State, April Fools' Day is just a day of joking and playing tricks on friends.These kinds of jokes are also called pranks(恶作剧).These jokes typically end in the prankster shouting "April Fools"!

Simple pranks, like telling a friend a funny lie or making prank phone calls, are still common.But major companies also get in on April Fools' Day in a much bigger way.A few years ago,on April 1,Starbucks announced it was introducing new coffee cup sizes-plenta and Micra.The very large cups,bigger than a human head,remained useful for customers even after finishing all that coffee.According to Starbucks,the cups could be used as a rain hat,a pot for plants,or a lampshade.

It did not take long for customers to catch on to the prank.More and more people use media or smartphone apps to play pranks on their friends on April Fools' Day.One very annoying smartphone app,Cat Facts,sends funny facts about cats to your friends 5 phones every day.