The full moon climbs over the eastern horizon (地平线) and hangs like a huge orange globe in the sky. A few hours later, the moon is overhead but seems to have changed. The huge orange globe has become a small silver disk. What has happened? Why has the orange color disappeared? Why does the moon seem so much smaller and farther away now that it is overhead?

    The moon appears orange on the horizon because we view it through the dust of the atmosphere. The overhead moon does not really shrink as it moves away from the horizon. Our eyes inform us that the overhead moon is farther away. But in this position the moon is actually closer to our eyes than when it is near the horizon.

    The change in size is a trick our eyes and minds play on us. When the moon is low in the sky, we can compare its size with familiar objects. It is easy to see that the moon is much larger than trees or buildings, for example. When the moon is high in the sky, however, it is hard to compare it with objects on earth. Compared to the vastness of the sky, the moon seems small.

    There is another reason why the moon seems to shrink. We are used to staring at objects straight ahead of us. When an object is difficult to see, our eyes have to try to focus on it. When we move our heads back to look up, we will try hard again. Looking at something from an unaccustomed position can fool you into believing an object is smaller or farther away than it is. However, scientists do not yet understand completely why the moon seems to shrink as it rises in the sky.

    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.

    Located in the checkroom in Union Station as I am, I see everybody that comes up the stairs.

Harry came in a little over three years ago and waited for the passengers from the 9:05 train.

    I remember seeing Harry that first evening. He wasn't much more than a thin, anxious kid then and I knew he was meeting his girl and that they would be married twenty minutes after she arrived. The passengers came up and I had to get busy. I didn't look toward the stairs again until it was nearly time for the 9:18 train and I was very surprised to see that the young fellow was still there.

    She didn't come on the 9:18 either, nor on the 9:40, and when the passengers from the 10:02 had all arrived and left, Harry was looking pretty desperate. He showed me the telegram he'd received: ARRIVE THURSDAY. MEET ME STATION. LOVE YOU. MAY.

    Harry met every train for the next three or four days, but in vain.

    Then came yesterday. I heard a cry and found that it was from Harry. He grabbed a girl who was small and dark. For a while they just hung there to each other laughing and crying and saying things without meaning. She'd say a few words like, "It was the bus station I meant" and he'd kiss her speechless and tell her the many things he had done to find her. What apparently had happened three years before was that May had come by bus, not by train, and in her telegram she meant "bus station," not "railroad station." She had waited at the bus station for days and had spent all her money trying to find Harry. Finally she got a job typing.

    "What?" said Harry. "Have you been working in town? All the time?"

    She nodded.

    "Didn't you ever come down here to the station?" He pointed across to a magazine stand. "I've been there all the time. I own it. I've watched everybody that came up the stairs."

    She began to look a little pale. Pretty soon she looked over at the stairs and said in a weak voice, "I never came up the stairs before. Harry, for three years, for three solid years, I've been right over there working right in this very station, typing, in the office of the stationmaster."

    Boomerang children who return to live with their parents after university can be good for families, leading to closer, more supportive relationships and increased contact between the generations, a study has found.

    The findings contradict research published earlier this year showing that returning adult children trigger a significant decline in their parents' quality of life and wellbeing.

    The young adults taking part in the study were “more positive than might have been expected” about moving back home – the shame is reduced as so many of their peers are in the same position, and they acknowledged the benefits of their parents' financial and emotional support. Daughters were happier than sons, often slipping back easily into teenage patterns of behaviour, the study found.

    Parents on the whole were more uncertain, expressing concern about the likely duration of the arrangement and how to manage it. But they acknowledged that things were different for graduates today, who leave university with huge debts and fewer job opportunities.

    The families featured in the study were middle-class and tended to view the achievement of adult independence for their children as a “family project”. Parents accepted that their children required support as university students and then as graduates returning home, as they tried to find jobs paying enough to enable them to move out and get on the housing ladder.

    “However,” the study says, “day-to-day tensions about the prospects of achieving different dimensions of independence, which in a few extreme cases came close to conflict, characterised the experience of a majority of parents and a little over half the graduates”.

    Areas of disagreement included chores, money and social life. While parents were keen to help, they also wanted different relationships from those they had with their own parents, and continuing to support their adult children allowed them to remain close.

    While it's books that make a library, being in lovely surroundings may provide inspiration and help you work a little bit harder. Here are some of the coolest libraries of the world.

    Library of Birmingham – Birmingham, U.K.

    The new Library of Birmingham is said to be not only Britain's biggest public library, but also the largest in Europe. Designed by Dutch architects, this replacement for the Birmingham Central Library was opened in 2013 and has a wealth of resources within its walls, including adults and kids' libraries, music collections, a Shakespeare Memorial Room, and even a gym room. Gardens crown the roof, while the changing seasons bring variations in the shadows and reflections inside.

    National Library of France – Paris, France

    The National Library of France, which now contains an astonishing collection of 30 million, dates back to the 14th century and this royal library was set up at the Louvre by King Charles V. The Library was moved to Rue de Richelieu site in 1868, with major design work carried out by French architects Henri Labrouste and, following his death, Jean-Louis Pascal. Here, the reading rooms are elegance itself. There are more than just books to be found.

    State Library of New South Wales – Sydney, Australia

    The public State Library of New South Wales holds the honor of being the oldest institution of its kind in Australia. It was originally set up as the Australian Subscription Library in 1826, but it wasn't until 1942 that its permanent home was ready. Designed by Sydney architect Walter Liberty Vernon and completed in 1910, the magnificent sandstone Mitchell Wing is one of the architectural highlights.

Seattle Central Library – Seattle, Washington, USA

    Seattle Central Library's distinctive design ensures it stands out. Architect Rem Koolhaas is one of the names attached to its design. Architects sought to envelop the 11-story building with "a layer of transparency", using a skin of glass and metal. The finished article houses about 1.45 million books and other things, as well as more than 400 computers available for public use. The building, which opened in 2004, was included on the American Institute of Architects' list of America's 150 favorite buildings in 2007.

Elephants might be the most well－known and well－loved animal in African wildlife. But conservation (保护) of the African elephant faces special difficulties. While the elephant population is half of what it was 40 years ago, some areas of Africa have more elephants than populated areas can support. That's why AWF scientists are studying elephant behavior, protecting habitats and finding ways for humans to live peacefully with elephants in Africa.

Years ago, overhunting and the ivory trade were the biggest threats to elephants' survival. Luckily, ivory bans (禁令), hunting rules and protected areas protect elephants from these dangers today.

The 21st century brings a different challenge to elephant conservation—land－use. Elephants walk across borders and outside parks and other protected areas. So they often destroy crops, causing conflicts (冲突) between local farmers and these big animals.

Successful conservation strategies (策略) must allow elephants to walk freely in their natural habitats while reducing conflicts between elephants and local people.

AWF researchers are searching for a way to give both elephants and people the space they need. The AWF is collecting information on elephant habitats and behavior. The information they gather will help to develop the widest possible space for elephants.

The AWF is helping elephants by protecting their habitats. And they also work with local farmers to improve their life in order to encourage them to protect rather than destroy elephants.