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.

    Millions of people along the US mid-Atlantic region should be preparing for severe snow, the National Weather Service has said. Forecasters say two feet of snow could fall over the weekend in some areas. A light dusting of snow on Wednesday night caused a traffic jam in Washington, but it is what lies ahead that is occupying the thoughts of millions of people living on the US east coast.

    Washington Mayor Muriel Bowser tweeted an apology to her constituents(选民), saying that the city government had “failed to use the necessary resources effectively in response to the snow-for that I am sorry.” Among those affected was President Barack Obama, whose motorcade spent an hour and 12 minutes trying to get him from an airport back to the White House-a trip that typically takes about a half hour.

    Routine commutes lasted up to three hours and some people abandoned their cars, after an inch fell-a small amount compared to what is expected on Friday and Saturday. Long queues have formed at supermarkets, as people expect shop closures over the weekend. “Heavy snow and blowing snow will cause dangerous conditions and will be threat to life and property,” the National Weather Service warned.

    Across the US east coast at a glance:

    Classes were cancelled at schools in Kentucky and Tennessee, the first states being affected by the storm.

    Washington has requested Humvees from the National Guard so that emergency responders can reach isolated(孤立的) people and places. Besides, its underground train system will close throughout the weekend.

    West Virginia Govemor Earl Ray Tomblin has activated the National Guard to assist.

    In Philadelphia, Pennsylvania officials are calling on people to keep large salt stockpiles and plough vehicles in good repair.

    On a hot summer weekend, Jorge Ayub saw the public beach north of Boston already crowded with nearly 1 million people drawn to the annual sand sculpture festival. Traffic on the nearby road was heavy, bands played music loudly, and later that night fireworks would light up the beach.

    And on the sand were four pairs of tiny shorebirds. These chicks(小鸟) were still too young to fly and a precious addition to the national endeavor to save a bird once down to 139 pairs in Massachusetts. It was Mr. Ayub's job. "Everyone made it," Ayub, a coastal ecologist reported at the end of the long weekend over the nests.

    Once common, piping plovers(笛鸻) were hunted and then squeezed out of their habitats(栖息地) by coastal development until, in 1986, the federal government listed the Atlantic Coastal birds as threatened. The bird's recovery has been halting. After three decades, the Atlantic population stands just under the 2,000-pair goal set by federal law.

    But the star has been Massachusetts, which has seen plovers increase to 687pairs from 139 pairs in 1986. One reason for that: "chick-sitting" in which conservationists sometimes spend all day watching over the birds.

    That progress has made Massachusetts the only East Coast state that decided to relax some Endangered Species Act restrictions: for example, to reduce the fenced-off areas and vehicle limits that have annoyed residents(居民).

    “Look at the stretch(一片土地), "Anyb says. "We had six nesting pairs between here and that bathhouse 600 yards away. By regulation, each nest should have 100 yards of fencing. We could have put up fencing and closed the beach all the way to the bathhouse."

    Instead, the plovers are surrounded in much smaller areas by "symbolic fencing". None of the 52 seawall entrances to the beach are closed. "If we put up too much fencing, people will be upset, and they are going to destroy it or walk right through the nesting areas," Ayub says. "By opening the beach, people are happier and the species does better."

Tuesday, 1^st September

    I had mixed feelings today, nervous, worried, happy, excited… My heart went down when Miss Chan, our head teacher, said that Matthew and Beth, two students from England, would spend three months with us! I was worried that I had to speak English so much! But at the end of the school day, I was happier than I thought: the morning with them today was more enjoyable than I expected.

    Today is the most unforgettable first day I have had! Matthew is fantastic! His English is clearer and easier to listen to than I thought. The other English student, Beth, is the most helpful girl I've ever met. There were lots of things to do on the first day. Beth offered to help Miss Chan put up all the notices. Of course, some of the credit (功劳) should also go to ME because I translated some of the notices for her. Miss Chan praised us!

    We finished all the preparations 10 minutes earlier than expected, then Beth and I talked for a while, Matthew sang several English songs and did some stand-up comedy (单人喜剧表演) at the party. We all praised him. When the bell rang to end the first school day, none of us wanted to leave.

    When I went back home, I had a little headache. I have probably spoken more English today than the whole of last year.

    It was really a happy day! I hope our friendship can continue, even after they gone back to England!